View source for Crusading movement

{{Short description|Framework of Christian holy war}}
{{good article}}
{{about|the theoretical, sociological, institutional, military, and financial dimensions of crusading|the expeditions for the Holy Land|Crusades}}
{{other uses|Crusade (disambiguation)|Crusader (disambiguation)}}
{{Use Oxford spelling|date=December 2024}}
{{Crusading movement sidebar|state=expanded}}
The '''Crusading movement''' was a major religious, political, and military endeavour of the [[Middle Ages]], traditionally dated from 1095, when [[Pope Urban II]], at the [[Council of Clermont]], proclaimed an armed expedition by [[Western Christendom]] in support of [[Eastern Christianity|Eastern Christians]] under Muslim rule. He framed it as a form of penitential [[Christian pilgrimage|pilgrimage]], offering spiritual rewards. By then, [[Papal supremacy|papal authority]] had grown through church reforms, and tensions with secular rulers encouraged the notion of holy war—combining [[Just war theory#Ancient Greece and Rome|classical just war theory]], [[The Bible and violence|biblical precedents]], and [[Augustine of Hippo|Augustine]]'s teachings on legitimate violence. Armed pilgrimage aligned with the era's [[Christocentrism|Christocentric]] and militant [[Catholicism]], sparking widespread enthusiasm. Western expansion was further enabled by [[Commercial revolution|economic growth]], the decline of older [[Mediterranean Sea|Mediterranean]] powers, and Muslim disunity. These factors allowed crusaders to seize territory and found four [[Crusader states]]. Their defence inspired successive [[Crusades]], and the [[Pope|papacy]] extended spiritual privileges to campaigns against other targets—Muslims in [[Iberian Peninsula|Iberia]], [[Paganism|pagans]] in the [[Baltic region|Baltic]], and other opponents of papal authority.

The papal-sanctioned wars fostered distinctive institutions and ideologies, having a great impact on medieval Europe and the Mediterranean. Though aimed primarily at the warrior elite through appeals to [[chivalric]] ideals, they depended on broad support from [[Priesthood in the Catholic Church|clergy]], townspeople, and peasants. [[Women in the Middle Ages|Women]], despite being discouraged, were involved as participants, proxies for absent crusaders, or victims. Although many crusaders were motivated by [[Crusade indulgence|indulgences]] (remission of [[Catholic hamartiology|sins]]), material gain also played a part. Crusading campaigns were typically initiated through [[Papal bull|papal bulls]], with participants pledging to join by "taking the [[Christian cross|cross]]"—sewing a cross onto their garments. Failure to fulfil [[Crusade vow|vows]] could result in [[Excommunication in the Catholic Church|excommunication]]. Periodic waves of zeal produced unsanctioned "[[popular crusades]]".

Initially funded through improvised means, later campaigns received more organized support via [[Papal income tax|papal taxes on clergy]] and the sale of indulgences. Core crusading forces were heavily armed [[Knight|knights]], backed by infantry, local troops, and naval aid from maritime cities. Crusaders secured their holdings by building powerful castles, and the fusion of chivalric and monastic ideals led to the rise of [[military orders]]. The movement extended Western Christendom and created new frontier states, some surviving into the [[early modern period]]. Crusading encouraged cultural exchange and left lasting marks on European art and literature. Despite the decline of core institutions during the [[Reformation]], anti-Ottoman "[[Holy League|holy leagues]]" sustained the tradition into the 18th{{nbsp}}century.

==Background==

The [[Crusades]] are commonly defined as [[religious war]]s waged by Western European warriors during the [[Middle Ages]] to capture Jerusalem.{{sfn|Hornby|2005|p=370}}{{sfn|Nicholson|2004|p=xlviii}} Related campaigns differed markedly in spatial reach, temporal limits, and motivating aims.{{sfn|Jotischky|2017|pp=10–11}}{{sfn|Nicholson|2004|pp=xl–xli, xlviii}} The wider crusading movement fostered distinctive institutions and ideologies that shaped society in Catholic Europe and neighbouring regions.{{sfn|Murray|2006|p=xxxi}}{{sfn|Lloyd|2002|p=65}}

===Classical just war theories===
{{See also|Later Roman Empire}}

[[File:BritLibRoyal5DVIIFolio067r.JPG|right|thumb|alt=A page from a centuries-old hand-written codex with a large initial letter in the text|A page from an early 12th-century [[manuscript]] of ''[[The City of God]]'' by [[Augustine]]]]

In [[classical antiquity]], [[Greek philosopher]]s and [[Ancient Rome|Roman]] jurists formulated [[just war theory|just war theories]] that later influenced crusading [[Christian theology|theology]]. [[Aristotle]] stressed the need for a just end, asserting "war must be for the sake of peace". [[Roman law]] required a {{transliteration|la|[[casus belli]]}}—just cause—and held that only [[Legitimacy (political)|legitimate]] authorities could declare war, with defence, restitution, and punishment considered acceptable grounds.{{sfn|Tyerman|2019|pp=13–14}}

Although the [[Bible]]—Christianity's core scripture—presents conflicting views [[The Bible and violence|on violence]],{{refn|group=note|The [[Old Testament]] depicts the [[Israelites]]' wars against their enemies as [[God in Judaism|divinely]] sanctioned, yet also includes the [[Thou shalt not kill|Fifth Commandment's]] prohibition of killing. In the [[New Testament]], Jesus states that "[[Live by the sword, die by the sword|all who take the sword will perish by the sword]]", but also declares, "[[Matthew 10:34|I have not come to bring peace but a sword]]."{{sfn|Asbridge|2012|pp=14–15}}}}{{sfn|Jaspert|2006|p=14}} the 4th-century [[Christianisation of the Roman Empire]] gave rise to Christian just war theory. Bishop [[Ambrose]], a former imperial official, was the first to equate enemies of the Christian state with those of the Church.{{sfn|Tyerman|2019|p=14}}{{sfn|Madden|2013|p=2}}

The empire was divided in 395.{{sfn|Lock|2006|p=358}} Fifteen years later, the [[Sack of Rome (410)|sack of the city of Rome]] led [[Augustine]]—Ambrose's student—to write ''[[The City of God]]''{{sfn|Backman|2022|pp=56–59}} in which he argued that the Bible's [[Thou shalt not kill|prohibition on killing]] did not apply to wars waged with divine approval.{{sfn|Tyerman|2019|pp=15, 482 (note 21)}} He held that just war must be declared by legitimate authority, pursued for a just cause once peaceful means had failed, and conducted with restraint and good intent.{{sfn|Tyerman|2019|p=14}}{{sfn|Jaspert|2006|p=15}} His reflections were nearly forgotten after the [[fall of the Western Roman Empire]] in 476.{{sfn|Tyerman|2019|p=14}}{{sfn|Jaspert|2006|pp=14–15}}

===Tripartite world===

{{Further|Early Middle Ages}}

From the ruins of the Western empire, [[Barbarian kingdoms|new Christian kingdoms]] emerged, largely ruled by [[Germanic peoples|Germanic]] warlords. Among this aristocracy, martial prowess and comradeship were core values. Clergy often praised their violence in pursuit of patronage, though the Church still deemed killing [[Catholic hamartiology|sinful]] and required [[penance]]—typically [[Fasting and abstinence in the Catholic Church|fasting]]{{sfn|Thomson|1998|pp=69–70}}—for [[absolution]].{{sfn|Jaspert|2006|pp=14, 30–31}}

Meanwhile, the [[Eastern Roman Empire|Eastern Roman (Byzantine) Empire]] endured, though much of its territory, including Jerusalem, was [[Early Muslim conquests|conquered]] by the rapidly expanding [[Rashidun Caliphate|Islamic Caliphate]] by the mid-7th{{nbsp}}century.{{sfn|Backman|2022|pp=126, 141–143}}{{sfn|Lock|2006|p=4}} [[Islam]]'s holiest text, the [[Quran]], addresses {{transliteration|ar|[[jihad]]}}—struggle to spread and defend the faith.{{refn|group=note|While both {{transliteration|ar|jihad}} and the crusades are forms of holy war, there is no evidence of a direct connection between them. The historian [[Paul M. Cobb]] attributes their similarities to "their common roots in a universal [[monotheism]] whose God is a [[Thou shalt have no other gods before me|jealous god]]".{{sfn|Cobb|2016|p=29}}}}{{sfn|Hillenbrand|2018|pp=89–91}}{{sfn|Jaspert|2006|p=75}} In the early 8th{{nbsp}}century, Muslim forces entered Europe, [[Muslim conquest of the Iberian Peninsula|conquering much of]] the [[Iberian Peninsula]]. Christians [[Dhimmi|under Muslim rule]] had to pay a special tax, the {{transliteration|ar|[[jizya]]}}.{{sfn|Cobb|2016|p=30}} As conquests stabilized, a threefold civilisational order emerged: a fragmented Western Europe, a weakened Byzantium, and an ascendant Islamic world.{{sfn|Backman|2022|pp=144–146}}

===Holy wars and piety===

Resistance to Muslim advance led to the creation of the small [[Kingdom of Asturias]] in north-western Iberia. Over time, this resistance evolved into an expansionist movement, regarded by locals as divinely sanctioned. In the 9th{{nbsp}}century, repeated invasions by non-Christian groups across Western Europe revived the notion of holy war:{{sfn|Jaspert|2006|p=15}} conflict authorized by a spiritual leader, pursued for religious aims, and rewarded with [[Salvation in Christianity|salvation]].{{sfn|Dennis|2001|p=31}} [[Pope Leo IV|Leo IV]] was the first pope to promise salvation in 846 to those defending [[Patrimony of Saint Peter|the papal territories]].{{sfn|Tyerman|2007|p=38}}{{sfn|Bysted|2014|pp=53–54}}

As warfare became constant, a new military class of mounted warriors emerged. Known as {{transliteration|la|milites}} in contemporary texts, they specialized in weapons like the heavy lance.{{sfn|Jaspert|2006|p=16}}{{sfn|Bull|2002|p=24}} To restrain their violence, church leaders launched the [[Peace of God]] movement.{{sfn|Backman|2022|pp=213–214}}{{sfn|Jaspert|2006|pp=17–18}} Ironically, efforts to curb bloodshed militarized the Church, as bishops increasingly raised armies to enforce the Peace.{{sfn|Morris|2001|p=144}}

[[File:Rotunda, Adomanan de locis santis.jpg|right|thumb|alt=A page from a manuscript depicting the plan of a church with lines and a series of five concentring rings|Plan of the [[Church of the Holy Sepulchre]] in an early 9th-century [[manuscript]] of {{Transliteration|la|[[De locis sanctis]]}} ('About Sacred Places'), a work by the Irish monk [[Adomnán]]]]

With weak central authority, regional strongmen seized control of [[Parish (Catholic Church)|parishes]] and [[abbey]]s, often appointing unfit clergy. Believers feared such irregularities invalidated [[Sacraments of the Catholic Church|sacraments]],{{sfn|Backman|2022|pp=214–215}}{{sfn|Jaspert|2006|p=25}} heightening anxiety over [[damnation]].{{sfn|Thomson|1998|pp=69–70}}{{sfn|Jaspert|2006|pp=30–31}} Sinners were expected to [[Confession (religion)|confess]] and perform penance to be reconciled with the Church. Since penance could be burdensome, priests began offering [[indulgence]]s—commuting penance into acts like almsgiving or [[Christian pilgrimage|pilgrimage]].{{sfn|Mayer|2009|pp=25–27}}{{sfn|Bysted|2014|p=20, 96}} Penitential journeys to Palestine held special value, as the region was the setting of [[Ministry of Jesus|Jesus's ministry]]{{sfn|Cobb|2016|pp=33–34}}{{sfn|Jaspert|2006|pp=21–22}} and home to the [[Church of the Holy Sepulchre]], believed to mark [[Crucifixion of Jesus|his crucifixion]] and [[Resurrection of Jesus|resurrection]].{{sfn|Tyerman|2019|pp=xxiii–xxv}}{{sfn|Jotischky|2017|pp=34–36}}

===Church reforms===

{{Main|Cluniac Reform|Gregorian Reform}}
{{Further|History of the papacy (1048–1257)}}

Fear of damnation spurred reform movements within the Church, which was regarded as the channel through which [[Grace in Christianity|divine grace]] was dispensed. In 910, [[Cluny Abbey]]'s foundation charter set a precedent by granting [[Christian monasticism|monks]] the right to [[Canonical election|freely elect]] their abbot. The [[Cluniac Reform]] spread rapidly, backed by aristocrats who valued the monks' [[Intercession|prayers for their souls]].{{sfn|Thomson|1998|pp=33–35}}{{sfn|Jaspert|2006|pp=27–28}} Cluniac houses answered solely to papal authority.{{sfn|Jaspert|2006|p=27}}{{sfn|Latham|2011|p=231}}

The popes, viewed as the successors of [[Saint Peter|Peter the Apostle]], claimed [[papal supremacy|supremacy]] over the Church, citing Jesus's [[Confession of Peter#Selection of Peter|praise for his apostle]].{{sfn|Thomson|1998|p=39}} In reality, Roman noble families [[Tusculan Papacy|controlled]] the papacy until Emperor [[Henry III, Holy Roman Emperor|Henry{{nbsp}}III]] entered Rome in 1053. He appointed clerics who launched the [[Gregorian Reform]] for the "[[Libertas ecclesiae|liberty of the church]]", banning [[simony]]—the sale of church offices—and giving [[Cardinal (Catholic Church)|cardinals]], senior clergy, the sole right to [[papal elections|elect the pope]].{{sfn|Thomson|1998|pp=82–85}}{{sfn|Jotischky|2017|p=25}} Andrew Latham, a scholar of [[international relations]], argues that the Gregorian Reform placed the Western Church in conflict with "a range of social forces within and beyond Christendom".{{sfn|Latham|2011|p=240}} By then, divisions in theology and liturgy between Western and Eastern [[Chalcedonian Christianity|mainstream Christianity]] had deepened,{{refn|group=note|The most evident differences between the two Christian communities lay in the [[filioque|unilateral Western alteration]] of the [[Nicene Creed]], and the eastern use of [[Baker's yeast|leavened]] rather than [[Unleavened bread|unleavened]] bread in the [[Eucharist]]—a central rite in Christian liturgy.{{sfn|Jaspert|2006|p=4}}}} leading to [[East–West Schism|mutual excommunications]] in 1054 and the eventual split between the western [[Roman Catholic Church|Roman Catholic]] and eastern [[Greek Orthodox Church|Orthodox Churches]], although [[Full communion|communion]] was not entirely severed.{{sfn|Jaspert|2006|p=4}}{{sfn|Jotischky|2017|pp=28–29}}

A spiritual revival took root as new monastic communities like the [[Carthusians]] and [[Cistercians]] emerged and the ''[[Rule of Saint Augustine]]'' spread among [[secular clergy]]. [[Christocentrism]]—a renewed focus on Christ's life and sufferings—also shaped the period, inspiring itinerant preachers.{{sfn|Jaspert|2006|p=29}}

==Prelude to the First Crusade==

{{See also|Medieval Warm Period}}

[[File:1071 CE, Europe.svg|right|upright=1.5|thumb|alt=Map depicting about twenty European states, and the lands of the neighbouring pagan peoples and Muslim powers|Europe on the eve of the [[Battle of Manzikert]]]]

Four major powers dominated the Mediterranean {{circa|1000}}: the [[Caliphate of Córdoba|Umayyads]] in [[Al-Andalus]] (Muslim Spain), the [[Fatimid Caliphate|Fatimids]] in Egypt, the [[Abbasid Caliphate|Abbasids]] (nominally) in the Middle East, and the Byzantine Empire. Within decades, all experienced serious crises, especially in the east, where [[Climate anomaly|climate anomalies]] triggered famine and instability.{{sfn|Tyerman|2019|pp=33–41, 47}}{{sfn|Ellenblum|2012|p=3}} In contrast, [[Medieval Warm Period|climate change]] benefitted Western Europe, fuelling economic and population growth.{{sfn|Tyerman|2019|p=47}}

Weakened by internal conflict, Al-Andalus fractured into [[taifa|small states]], vulnerable to Christian expansion—a process called the {{transliteration|es|[[Reconquista]]}}.{{sfn|Cobb|2016|pp=60–70}} In Egypt and Palestine, repeated failure of the [[Nile flood|Nile's floods]] led to famine and interreligious tension. In 1009, the Fatimid caliph [[al-Hakim bi-Amr Allah|Al-Hakim]] ordered the [[Destruction of the Church of the Holy Sepulchre|destruction of the Holy Sepulchre]],{{refn|group=note|A papal [[encyclical]]—allegedly issued by [[Pope Sergius IV]] after the Holy Sepulchre's destruction—states that he intended to lead a fleet east and rebuild the church, but the document is a late 11th-century forgery produced at [[Moissac Abbey]].{{sfn|Mayer|2009|p=17}}}}{{sfn|Ellenblum|2012|pp=46–47}} though it was later rebuilt with Byzantine support.{{sfn|Lock|2006|p=12}} Meanwhile, [[Turkoman (ethnonym)|Turkoman]] migrations from [[Central Asia]] destabilized the Middle East. The Turkoman chief {{nowrap|[[Tughril I]]}}, of the [[Seljuk dynasty|Seljuk clan]], seized Baghdad in 1055;{{sfn|Ellenblum|2012|pp=61–96}}{{sfn|Lock|2006|pp=12–14}} his successor, [[Alp Arslan]], defeated the Byzantines at [[Battle of Manzikert|Manzikert]] in 1072, opening [[Anatolia]] to Turkoman settlement.{{sfn|Cobb|2016|pp=71–72}}{{sfn|Jotischky|2017|p=45}}

As traditional powers declined, Italian merchants gained control of Mediterranean trade.{{sfn|Tyerman|2019|p=57}} The [[Italo-Normans|Normans]], originating in northern France, [[Norman conquest of southern Italy|conquered southern Italy and Sicily]] by 1091.{{sfn|Backman|2022|pp=287–288}}{{sfn|Cobb|2016|pp=49–60}} Their expansion threatened papal interests, prompting [[Pope Leo IX]] to launch a military campaign against them. Although [[Battle of Civitate|his campaign failed]], he had promised absolution to its participants{{sfn|Bysted|2014|p=57}}{{sfn|Jotischky|2017|p=26}}—a sign of the reform papacy's willingness to invoke spiritual incentives for warfare.{{sfn|Morris|2001|pp=144–145}}

For Western warriors, warfare offered a path to land and power.{{refn|group=note|The [[Hauteville dynasty|Hautevilles]] of Sicily, descended from the minor Normandian lord [[Tancred of Hauteville|Tancred]] and his eleven{{nbsp}}sons, are a frequently cited example.{{sfn|Bartlett|1994|p=49}}}}{{sfn|France|1999|pp=188–189}} These ambitions often aligned with reformist popes, who granted absolution to those fighting Muslim powers in Sicily and Iberia.{{refn|group=note|[[Pope Alexander II]] offered absolution to Normans campaigning [[Muslim Sicily]] and promised remission of sins to warriors departing for Iberia.{{sfn|Bysted|2014|pp=57–58}}}}{{sfn|Bull|2002|p=18}}{{sfn|Bysted|2014|pp=57–58}} As these territories were once Christian, papal attention soon turned to Palestine. [[Pope Gregory VII]] proposed a campaign to reclaim Jerusalem in 1074, though it never materialized.{{sfn|Tyerman|2007|p=49}} Two years later, disputes over papal and royal authority ignited the [[Investiture Controversy]], reviving interest in just war theory.{{sfn|Jotischky|2017|pp=25–27}}{{sfn|Backman|2022|pp=301–302}} [[Anselm of Lucca]], a [[canon lawyer]], compiled Augustine's writings to argue that war aimed at preventing sin could be an act of love. The theologian [[Bonizo of Sutri]] considered those who died in such wars [[Christian martyr|martyrs]].{{sfn|Jotischky|2017|pp=25–27}}{{sfn|Bysted|2014|p=209}} These ideas shaped the notion of penitential warfare: the belief that fighting for a just cause could serve as penance.{{sfn|Riley-Smith|2002a|p=78}}

==Crusading campaigns==

The fusion of classical just war theory, biblical views on warfare, and Augustine's teaching on legitimate violence provided the Western Church with an ideological framework for military engagement.{{sfn|Bull|2002|p=18}} By the late 11th{{nbsp}}century, amid religious revival and heightened concern over sin, the papacy was well positioned to mobilize the warrior class's values.{{sfn|Jaspert|2006|p=33}}

===First Crusade===
{{Main|First Crusade}}
{{See also|Siege of Antioch|Siege of Jerusalem (1099)}}

[[File:1099 Siege of Jerusalem.jpg|right|thumb|alt=A miniature depicting the walls of a large fortress and dozens of armed people attacking it using siege machines|[[Siege of Jerusalem (1099)]] (from a 13th-century manuscript of [[William of Tyre]]'s chronicle)]]

Facing Turkoman incursions, the Byzantine emperor [[Alexios I Komnenos]] sought military aid from [[Pope Urban II]] in 1095. Seeing this as a chance to reassert papal authority, Urban called for a campaign against the Turkomans at the [[Council of Clermont]], offering spiritual rewards to participants.{{sfn|Asbridge|2012|pp=34–38}}{{sfn|Jotischky|2017|p=54}} The historian Jonathan Riley-Smith views this as a "revolutionary appeal" that linked warfare to pilgrimage.{{sfn|Riley-Smith|2002a|p=78}}

Urban's appeal sparked unexpected enthusiasm. In early 1096, more than 20,000{{nbsp}}poorly organized Crusaders set off in what became the [[People's Crusade]]. Most perished or [[Battle of Civetot|were massacred]] en route.{{sfn|Lloyd|2002|pp=35–36}}{{sfn|Lock|2006|pp=20–21}} A second wave followed between August and October in that year, comprising at least 30,000{{nbsp}}warriors and as many non-combatants, led by prominent aristocrats including [[Raymond of Saint-Gilles]], [[Bohemond I of Antioch|Bohemond of Taranto]], and [[Godfrey of Bouillon]].{{sfn|Asbridge|2012|pp=43–46}}{{sfn|Jaspert|2006|pp=40–45}} They advanced through fragmented Muslim-held territories and captured the cities of [[Edessa]], [[Antioch]], and Jerusalem by July 1099.{{sfn|Irwin|2002|pp=215–217}}{{sfn|Lock|2006|pp=20–26}}

===Crusades for the Holy Land===
{{main|Crusades}}
{{Further|Crusade of 1101|Second Crusade|Third Crusade|Fourth Crusade|Fifth Crusade|Sixth Crusade|Seventh Crusade|Eighth Crusade}}

The first Crusaders consolidated their conquests into four [[Crusader states]]: [[County of Edessa|Edessa]], [[Principality of Antioch|Antioch]], [[Kingdom of Jerusalem|Jerusalem]], and [[County of Tripoli|Tripoli]]. Their defence prompted new campaigns, [[Crusade of 1101|the first]] as early as 1101. Several expeditions, especially those led by monarchs, became numbered.{{sfn|Lloyd|2002|p=37}}{{sfn|Lock|2006|pp=137–224}} These campaigns brought about near-continuous warfare in the region, drawing forces from across the wider world, including crusaders from Western Europe, [[slave soldiers]] from sub-Saharan Africa, and [[nomad|nomadic]] horsemen from the [[Eurasian steppes]].{{sfn|Tibble|2025|pp=16–17}} [[Siege of Edessa (1144)|Edessa's fall]] in 1144 to the Turkoman leader [[Imad al-Din Zengi]] triggered the [[Second Crusade]], led by [[Louis VII of France]] and [[Conrad III of Germany]], which failed [[Siege of Damascus (1148)|in 1148]].{{sfn|Lock|2006|pp=147–150}}{{sfn|Madden|2013|pp=50–59}} Zengi's son, [[Nur al-Din Zengi|Nur al-Din]], unified Muslim Syria and dismantled the Fatimid Caliphate. These lands came under the control of [[Saladin]], an ambitious [[Kurds|Kurdish]] general. In 1187, he destroyed the Jerusalemite field army [[Battle of Hattin|at Hattin]] and captured most Crusader territory, including the city of Jerusalem.{{sfn|Jotischky|2017|pp=119–129}}{{sfn|Asbridge|2012|pp=343–363}} 

The resulting crisis triggered the [[Third Crusade]], led by [[Frederick I, Holy Roman Emperor|Emperor Frederick I]], [[Richard I of England]], and [[Philip II of France]]. Although Jerusalem remained under Muslim rule, the Crusader states endured, and the [[Kingdom of Cyprus]] was founded on former Byzantine territory.{{sfn|Lock|2006|pp=151–155}}{{sfn|Madden|2013|pp=77–90}} Later Crusades focused on recovering Jerusalem, but the [[Fourth Crusade|Fourth]] was diverted by [[Alexios IV Angelos|a Byzantine claimant]], leading to the [[sack of Constantinople]] and the creation of a [[Latin Empire of Constantinople|Latin Empire]] in Byzantine territory in 1204.{{sfn|Madden|2013|pp=93–114}}{{sfn|Lock|2006|pp=82–87, 156–161}} The [[Fifth Crusade]] against Egypt failed in 1217–21. The [[Sixth Crusade|Sixth]] regained Jerusalem in 1229 through negotiations by the excommunicated [[Frederick II, Holy Roman Emperor|Emperor Frederick II]], but [[Siege of Jerusalem (1244)|the city was sacked]] in 1244 by [[Khwarazmian army between 1231 and 1246|Khwarazmian raiders]].{{sfn|Lock|2006|pp=106, 167–170}} Its loss prompted [[Louis IX of France]] to launch the [[Seventh Crusade]] in 1248, which ended [[Battle of Fariskur (1250)|in defeat]].{{sfn|Madden|2013|pp=156–155}} 

After the [[Mamluks of Egypt|Mamluks]] supplanted the [[Ayyubid dynasty|Ayyubids]]—Saladin's family—as the dominant Muslim power in the Levant, Sultans [[Baybars]] and [[Qalawun]] waged systematic campaigns against the Crusader states. Louis{{nbsp}}IX mounted the [[Eighth Crusade]], but died in 1270, and anarchy followed. In 1291 Qalawun's son [[Al-Ashraf Khalil|Khalil]] seized the last Crusader strongholds in the [[Holy Land]].{{sfn|Madden|2013|pp=162–175}} Despite continued proposals to reclaim Jerusalem,{{refn|group=note|Notable authors of crusade treatises include [[James I of Aragon]], [[Charles II of Sicily]], the last Templar grand master [[James of Molay]], the French minister [[William of Nogaret]], the Armenian aristocrat [[Hayton of Corycus]], the Franciscan friar [[Fidentius of Padua]], and the mystic [[Ramon Lull]].{{sfn|Tyerman|2019|p=379}}}} efforts were hampered by events such as the [[Hundred Years' War]].{{sfn|Jotischky|2017|pp=266–271}}{{sfn|Housley|2002|pp=258–266}}

===Other theatres of war===

{{Main|Crusades against Christians|Northern Crusades|Iberian Crusades}}

[[File:Zespół Zamku Krzyżackiego MALBORK 01.jpg|right|thumb|alt=A large walled brick fortress with towers and inner castles on a river|[[Malbork Castle]] of the [[Teutonic Order]] in [[Prussia]]]]

The historian Simon Lloyd notes that "crusading was never necessarily tied" to the Holy Land.{{sfn|Lloyd|2002|pp=38–39}} As early as 1096, Pope Urban urged Catalan nobles to remain in Iberia, promising equal spiritual rewards.{{sfn|O'Callaghan|2003|pp=32–33}} The [[First Lateran Council]] in 1123 officially equated campaigns against the [[Moors]] (Iberian Muslims) with Crusades.{{sfn|Madden|2013|p=116}}{{sfn|O'Callaghan|2003|p=38}} These Iberian Crusades drove Christian expansion, reducing Al-Andalus to the [[Emirate of Granada]] by 1248.{{refn|group=note|In 1095, the [[Almohads]]—a newly emerged [[Islamic fundamentalism|fundamentalist Muslim]] power—inflicted a heavy defeat on the [[Kingdom of Castile|Castilian]] royal army [[Battle of Alarcos|at Alarcos]], but were decisively routed by a large crusader army [[Battle of Las Navas de Tolosa|at Las Navas de Tolosa]] in 1213.{{sfn|Madden|2013|p=117}}{{sfn|Lock|2006|pp=80, 90}}}}{{sfn|Madden|2013|p=117}}

Some crusades emerged from conflict with pagan groups.{{sfn|Lloyd|2002|p=39}} In 1107–08, [[Duchy of Saxony|Saxon]] leaders referred to the pagan Slavic [[Wends]]' territory as "Our Jerusalem", though anti-Wendish war was recognized as [[Wendish Crusade|a crusade]] only in 1147. From then, northern German, Danish, Swedish, and Polish rulers launched papally sanctioned campaigns against Slavic, [[Balts|Baltic]], and [[Baltic Finnic peoples|Finnic]] tribes—collectively termed as the [[Northern Crusades]]. By the 1260s, leadership had passed to the [[Teutonic Order]]'s warrior monks.{{sfn|Jaspert|2006|pp=125–128}}{{sfn|Bartlett|1994|p=262}} 

Crusading zeal also turned [[Crusades against Christians|against Christian foes]] of the papacy. "Political crusades" were launched against Emperor Frederick{{nbsp}}II, his heirs, and rebellious papal [[vassal]]s.{{refn|group=note|The first "political crusade" was proclaimed by Pope Innocent{{nbsp}}III in 1199 against [[Markward of Anweiler]], a German aristocrat who contested Innocent's [[regency]] claim in [[Kingdom of Sicily|Sicily]].{{sfn|Lloyd|2002|p=39}}{{sfn|Lock|2006|pp=155–156}}}}{{sfn|Lloyd|2002|pp=39–40}} From 1209, Pope Innocent{{nbsp}}III targeted [[Heresy in Christianity|heretics]]—Christians who rejected Church doctrine{{sfn|Jaspert|2006|p=135}}—and Crusades were proclaimed [[Reconquest of Constantinople|after 1261]] against the restored Byzantine Empire.{{sfn|Lock|2006|pp=181–183}}

===Later crusades===

Despite internal divisions, the {{transliteration|la|Reconquista}} continued, ending with the [[Granada War|conquest of Granada]] by [[Crown of Castile|Castile]] and [[Crown of Aragon|Aragon]] in 1492.{{sfn|Housley|2002|pp=267, 282–283}}{{sfn|O'Callaghan|2003|pp=209–214}} In the early 14th{{nbsp}}century, {{Transliteration|de|Preussenreise}}—seasonal anti-pagan raids in the Baltic—became a hallmark of [[chivalry|chivalric culture]].{{sfn|Jotischky|2017|p=277}} The historian Eric Christiansen called these "an interminable crusade".{{sfn|Christiansen|1997|p=164}}{{sfn|Housley|2002|p=273}} In the Western Mediterranean, popes also proclaimed crusades against Christian enemies, including [[Aragonese Crusade|Aragon]], and [[War of the Sicilian Vespers|Sicily]]. During the [[Western Schism]] (1378–1417), rival popes called crusades against each other's supporters.{{refn|group=note|At the onset of the schism, [[Pope Urban VI|Urban VI]] granted crusading privileges to the English bishop [[Henry le Despenser]] to attack the Flemish supporters of his rival, [[Antipope Clement VII|Clement VII]], and to the English duke [[John of Gaunt]] to campaign against [[John I of Castile]], who also backed Clement.{{sfn|Tyerman|2007|pp=900–901}}}}{{sfn|Housley|2002|p=268}}{{sfn|Lock|2006|pp=198–199}}

Extensive piracy in the Mediterranean revived anti-Muslim crusading in the mid-14th{{nbsp}}century.{{refn|group=note|The [[Aydinids]] lordship in Anatolia, infamous for its naval raids, was targeted by [[Smyrniote crusades|three crusades]] between 1333 and 1347.{{sfn|Tyerman|2019|p=397}}}}{{sfn|Tyerman|2019|pp=396–397}} International campaigns targeted the rising [[Ottoman Empire]] but failed to stop the [[fall of Constantinople]] in 1453.{{sfn|Tyerman|2019|pp=397, 403–410}} The [[Hussite Wars]] reignited anti-heretical crusades in 1420,{{sfn|Housley|2002|pp=280–282}}{{sfn|Nicholson|2004|pp=65–74}} and the [[Reformation]] saw indulgences granted to Catholics fighting [[Protestants]].{{sfn|Constable|2001|pp=6–7}} Although the Reformation weakened papal authority, the papacy continued to promote crusades, helping form anti-Ottoman "[[Holy League|holy leagues]]" well into the early 18th{{nbsp}}century.{{sfn|Nicholson|2004|pp=77–88}}{{sfn|Housley|2002|p=290}}

==Theory and theology==

{{Main|Crusade indulgence}}

Pope Urban{{nbsp}}II's call at Clermont introduced a remarkably novel concept for most listeners.{{sfn|Tyerman|2011|pp=22–23}} Though Western Christians had accepted divinely sanctioned warfare, its full theological and legal justification was still evolving.{{sfn|Nicholson|2004|p=5}}

[[File:Heidelberg cpg 144 Elsässische Legenda Aurea 338r St. Patricks Fegefeuer.jpg|right|thumb|alt=Nude people are being burnt in fire by a devil|Sinners' (temporal) punishment in the [[Purgatory]] (a page from the early 15th-century Alsatian manuscript of the ''[[Golden Legend]]'')]]

Initially seen as a unique event [[Deus volt|prompted by divine intervention]], the expanding movement soon required stronger legal foundations.{{sfn|Tyerman|2011|pp=23–24}} The {{transliteration|la|[[Decretum Gratiani]]}}, an influential collection of church law, permitted warfare {{circa|1140}}—but only against heretics.{{sfn|Jaspert|2006|p=65}}{{sfn|Tyerman|2011|p=24}} Within decades, jurists like [[Huguccio]] extended this to Muslims, citing just intent, recovery of Christian lands, and retaliation for violence.{{sfn|Tyerman|2011|p=24}} Crusades outside the Holy Land were often justified by the perceived spiritual importance of those regions, prompting writers like [[Arnold of Lübeck]] to depict Livonia as Mary the Virgin's dowry.{{sfn|Cassidy-Welch|2023|pp=30, 38}} Although originally framed as defensive, the Northern Crusades soon focused on conversion,{{sfn|Jotischky|2017|p=218}} while Crusades against anti-papal Christians were portrayed as essential to safeguard the Holy Land.{{sfn|Tyerman|2019|p=359}}

Soon after Clermont, the [[chronicle]]r [[Guibert of Nogent]] wrote that "God has instituted in our times holy wars" so that both knights and commoners might gain salvation.{{sfn|Riley-Smith|2002a|p=78}} Yet the nature of the spiritual rewards granted to the First Crusaders remains unclear. Some sources mention cancellation of temporal penance, others full remission of sins.{{refn|group=note|Bishop [[Lambert of Arras]], present at Clermont, wrote that those departing for the Holy Land "could substitute this journey for all penance". Another participant, [[Robert of Rheims]] said that Urban had granted the remission of sins to the Crusaders, while a third eyewitness, [[Baldric of Dol]] noted the Pope instructed the bishops to absolve only those who had confessed.{{sfn|Bysted|2014|pp=46–47, 49}}}}{{sfn|Jaspert|2006|p=31}}{{sfn|Jotischky|2017|p=54}} Pope Urban referred to {{transliteration|la|remissio peccatorum}} ("remission of sins") in one letter, and in another promised absolution of all penance to those travelling to the Holy Land "only for the salvation of their souls", provided they confessed.{{sfn|Bysted|2014|pp=67–68}}

Theological debate on indulgences began {{circa|1130}}. [[Peter Abelard]] sharply criticized the practice, although most later theologians accepted it.{{sfn|Bysted|2014|pp=85–112}} The [[Fourth Lateran Council]] codified Crusade indulgences in 1215, declaring that "sins repented by heart and confessed with mouth" would be remitted. The theological basis remained unsettled until {{circa|1230}}, when the "[[Treasury of Merit]]" doctrine emerged, which held that the Church could grant indulgences from merit earned through Christ and the martyrs.{{sfn|Bysted|2014|p=132–135}}{{sfn|Jotischky|2017|p=192}} Occasionally, offenders of particular crimes—such as arsonists, violators of trade embargoes with Muslims, and assailants of clergy—were granted indulgence.{{sfn|O'Callaghan|2003|p=103}} Debate over the scope of the indulgence continued, with [[Bonaventure]] arguing that indulgences did not apply to those dying before fulfilling their vow, and [[Thomas Aquinas]] maintaining that penitent crusaders who confessed would attain salvation even if they died before departing.{{sfn|Bysted|2014|pp=142–143}}

==Crusaders==

{{See also|List of principal leaders of the Crusades}}

Crusaders' motives are inherently difficult to determine. Although contemporary sources emphasize religious fervour, secular ambitions also played a role because holding conquests required sustained Western presence.{{refn|group=note|[[Robert of Rheims]]'s version of Pope Urban's speech explicitly mentions the prospect of material gains.{{sfn|France|1999|p=205}}}} Many participants enlisted for pay.{{sfn|Tyerman|2019|p=202}} Most saw no contradiction between piety and material gain, such as [[Booty (loot)|booty]].{{sfn|Jotischky|2017|p=39}}{{sfn|Phillips|2014|p=21}} Some sought fame; others, as noted by the historian Jonathan Phillips, the appeal of long-distance travel.{{sfn|Phillips|2014|pp=21–23}} Some criminals escaped harsher punishment by taking the cross.{{refn|group=note|A notable case is Amanieu of Astarac, a French aristocratic outlaw sentenced in 1323 to two years of military service in Cilician Armenia or Cyprus.{{sfn|Tibble|2025|p=41}}}}{{sfn|Tibble|2025|p=41}} The medievalist Andrew Jotischky suggests figures like the robber baron [[Thomas of Marle]] saw crusading as an opportunity for unpunished violence.{{sfn|Jotischky|2017|pp=39–40}}

===Knights and aristocrats===

[[File:Peraldus Knight.jpg|right|thumb|alt=An armed horseman holding a sword, a lance, and a shield, with an angel over him|Allegory presenting a [[knight]] prepared to fight the [[seven deadly sins]] (from the 12th-century {{Transliteration|la|Summa Vitiorum}} ('Summa of Vice') by [[William Perault]])]]

Pope Urban directed his appeal at Clermont to the country's military elite.{{sfn|Jotischky|2017|p=56}} By then, the {{transliteration|la|milites}}—once a broad category—had become a distinct warrior caste, though knighthood would not be fully equated with nobility until the late 12th{{nbsp}}century.{{sfn|Tyerman|2019|p=53}} Aristocrats valued visible piety, and crusading offered a new outlet for what Madden calls their "simple and sincere love of God".{{sfn|Madden|2013|pp=12–13}}

The warrior lifestyle entailed habitual sin, yet offered few chances for penance. Barefoot pilgrimages stripped knights of their symbols—arms and warhorses. Urban's message allowed them to maintain their identity without jeopardizing salvation.{{sfn|Bull|2002|p=33}}{{sfn|Riley-Smith|2002a|pp=78–79}} Crusade rhetoric mirrored their values, invoking [[vassalage]] and honour.{{sfn|Jaspert|2006|p=20}} Preachers cast Christ as a feudal lord, summoning knights to defend his stolen patrimony as {{Transliteration|la|milites Christi}} ("Christ's warriors").{{refn|group=note|Originally, {{Transliteration|la|miles Christi}} denoted clergy who wealded spiritual arms in God's service.{{sfn|Jaspert|2006|p=19}}}}{{sfn|Madden|2013|p=9}}{{sfn|France|1999|p=205}}

Crusading decisions were often collective, made within noble households led by influential lords.{{sfn|Jotischky|2017|p=16}} Success brought prestige, and crusading kin could make participation a family tradition.{{refn|group=note|For instance, three sons of [[William I, Count of Burgundy]] joined the First Crusade; one grandson and one granddaughter participated in a crusade in the 1120s; and seven descendants took part in the Second Crusade.{{sfn|Riley-Smith|2002a|pp=81, 86}}}}{{sfn|Riley-Smith|2002a|pp=72, 81}} Yet failure meant disgrace or financial ruin.{{sfn|Riley-Smith|2002a|p=72}}{{sfn|Tyerman|2019|pp=491 (note 37)}} Even in the [[Late Middle Ages]], chivalric ideals fuelled two expeditions: the 1390 [[Barbary Crusade]] and the 1396 [[Crusade of Nicopolis]].{{sfn|Madden|2013|p=181}}

===Clergy===

Although violence conflicted with their vocation, clerics often joined crusades.{{sfn|Nicholson|2004|p=xlii}} At Clermont, Bishop [[Adhemar of Le Puy]] was the first to vow the journey to Jerusalem.{{sfn|Riley-Smith|2002a|p=1}} The Fourth Lateran Council explicitly permitted clerics to join for up to three years without forfeiting their [[benefice]]s.{{sfn|Brundage|1997|p=150}} Secular clergy typically served as [[chaplain]]s or administrators;{{sfn|Jaspert|2006|p=62}}{{sfn|Tyerman|2019|p=226}} senior churchmen led troops.{{refn|group=note|Among the first crusading prelates, Archbishop [[Daimbert of Pisa]] led a fleet of 120 ships to the Levant in 1099.{{sfn|Lock|2006|pp=25, 234}}{{sfn|Tyerman|2007|p=161}} In the first Northern Crusade, seven bishops led an assault on the town of [[Demmin]].{{sfn|Christiansen|1997|p=55}}}}{{sfn|Tyerman|2019|p=226}} Influential prelates also helped initiate the Northern Crusades.{{refn|group=note|Archbishop [[Eskil of Lund]] threatened [[Valdemar I of Denmark]] with excommunication to compel an attack on the pagans on the island of [[Rügen]], then joined the campaing himself. His successor, [[Absalon]], as the historian Eric Christiansen notes, spent "most of his life in the sadle or on the gangway of his ship".{{sfn|Christiansen|1997|pp=60–61}}}}{{sfn|Jaspert|2006|p=126}} Despite vows like {{transliteration|la|stabilitas voci}} ("stability of place"), monks joined too.{{sfn|Nicholson|2004|p=xlii}}{{sfn|Jaspert|2006|p=62}} Cistercians and [[Premonstratensians|Premonstratensian]]s even took up arms occasionally, especially in the Baltic.{{refn|group=note|The Cistercian monk [[Berno, Apostle of the Obotrites|Bern]] became a missionary bishop to the [[Abodrites]] and took part in the [[Siege of Arkona|1168 invasion]] of Rügen.{{sfn|Christiansen|1997|p=62}}}}{{sfn|Christiansen|1997|pp=59–60}}

===Patricians===

Urban elites played a vital role in several crusades.{{sfn|Tyerman|2019|p=227}} Fleets from Genoa, Pisa, and [[Republic of Venice|Venice]] helped establish and secure the Crusader states,{{refn|group=note|The Genoese patrician [[Guglielmo Embriaco]] joined the crusaders at the siege of Jerusalem in June 1099, while the Venetian Giovanni Michiel helped to capture the city of [[Haifa]] in the late summer of 1100.{{sfn|Lock|2006|pp=384–386}}}} gaining in return commercial privileges and city quarters.{{sfn|Lock|2006|pp=382–387}} The city of [[Lübeck]] supported the conquest of Prussia.{{sfn|Christiansen|1997|p=104}} Iberian towns owed military service under royal charters—often replaced by a special tax called {{transliteration|es|fonsadera}}.{{sfn|O'Callaghan|2003|p=129}}

{{Quote box
 |title     = Excerpt from the {{Transliteration|la|[[Pactum Warmundi]]}} about the Venetians' privileges (1123–24)
 |quote     = In every city ...the Venetians shall have a church and one entire street of their own; also a square and a bath and an oven to be held forever by hereditary right, free from all taxation as is the king's own property.
 |author    = [[William of Tyre]]
 |source    = ''A History of Deeds Done Beyond the Sea''{{sfn|Phillips|2014|p=226}}
 |align     = center
 |width     = 66.6%
 |bgcolor   = #F5FAFF
 |title_bg  = #CEE0F2
 |qalign    = left
 |salign    = right
 }}

During the Fourth Crusade, Doge [[Enrico Dandolo]] convinced fellow leaders to [[Siege of Zara|capture Zadar]], a Catholic city in Dalmatia, and later advocated the assault on Constantinople. After its sack, Venice gained control of several [[Aegean islands]], establishing patrician-led lordships.{{refn|group=note|[[Marco I Sanudo]] seized [[Naxos]] and the nearby islands, establishing the [[Duchy of the Archipelago]].{{sfn|Lock|1995|pp=147–148}}}}{{sfn|Jaspert|2006|pp=52–53}}{{sfn|Phillips|2014|pp=184–200}} [[Marino Sanuto the Elder|Marino Sanudo Torsello]], a Venetian writer, became a key crusading theorist,{{sfn|Carr|2016|pp=68–69}} and proposed a naval alliance against Aegean pirates, uniting Catholic powers with Genoese and Venetian island lords.{{sfn|Carr|2016|pp=68–69}}

===Commoners===

[[File:Croisade des Pastoreaux Britisch Librairy.jpg|left|thumb|alt=A group of men armed with bludgeons at a fortress manned with two armed men with a nude baby falling from the walls|Shepherds attack a fortress during the [[Shepherds' Crusade (1320)|1320 Shepherds' Crusade]] (a miniature from the late 14th-century {{Transliteration|fr|Chroniques de France ou de St-Denis}}).]]

The historian [[Christopher Tyerman]] observes that crusading was "as much as a phenomenon of artisans as of knights, of carpentry as much as of castle". Commoners filled essential roles in Crusader armies as foot soldiers, sailors, archers, engineers, and [[squire]]s. They were typically young men of modest means who joined for pay.{{sfn|Tyerman|2019|pp=227–228}}

Following Clermont, Pope Urban barred clergy from accepting vows from those unable to fight and annulled existing ones.{{sfn|Madden|2013|p=10}} Nonetheless, the People's Crusade consisted almost entirely of unarmed commoners,{{sfn|Kostick|2008|p=290}} inspired by charismatics like [[Peter the Hermit]].{{sfn|Asbridge|2012|p=40}} In the First Crusade's noble-led armies, the number of non-combatants nearly matched the number of fighters. The historian [[Conor Kostick]] describes them "a slice of European society on the march".{{sfn|Kostick|2008|pp=289–290}} Chroniclers like [[Raymond of Aguilers]] called common Crusaders as {{transliteration|la|pauperes}} ("the poor or defenceless") and saw their presence as vital for divine favour.{{sfn|Kostick|2008|pp=30–34}} Unlike nobles, captured commoners were often tormented or killed rather than ransomed.{{sfn|Friedman|2001|p=124}}

Grassroots crusading zeal later inspired mass movements known as [[popular crusades]].{{sfn|Tyerman|2019|p=259}}{{sfn|Dickson|2006|p=975}} These included the 1212 [[Children's Crusade]], led by two charismatic boys;{{refn|group=note|Contemporary sources called the participants as {{transliteration|la|pueri}} ('children'), giving the movement its name.{{sfn|Tyerman|2019|p=260}}}} the [[Shepherds' Crusade (1251)|1251]] and [[Shepherds' Crusade (1320)|1320]] Shepherds' Crusades, the former sparked by a letter allegedly from the [[Virgin Mary]]; and the 1309 [[Crusade of the Poor]]. None reached the Holy Land, and both Shepherds' Crusades were forcibly disbanded.{{sfn|Lock|1995|pp=166, 187, 190}}{{sfn|Tyerman|2019|pp=258–260}} In 1456, a peasant Crusader army helped repel the Ottomans at the [[Siege of Belgrade (1456)|Siege of Belgrade]]. This success encouraged future efforts to mobilize peasants in anti-Ottoman crusades, but [[György Dózsa|in 1514]] a crusading peasant army in Hungary turned on their lords.{{sfn|Tyerman|2019|pp=411–412}}

==Enemies and contacts==

Except for the Mongols, the Crusaders rarely faced unfamiliar enemies. These foes were cast as aggressors, thereby providing a just cause for war against them.{{sfn|Riley-Smith|2005|p=130}} Conquest and colonisation created multi-ethnic societies, making interethnic relations integral.{{sfn|Bartlett|1994|p=197}} In Iberia and the Crusader states, relations with natives followed the pre-conquest {{transliteration|ar|dhimmi}} model.{{sfn|Riley-Smith|2005|p=131}}

===Muslims===

[[File:Double page from the Qur'an manuscript containing the opening to juz' 13 (DMA K.1.2014.574.1).jpg|right|thumb|alt=A double page from a manuscript with Islamic calligraphy|A double page from a 12th-century [[manuscript]] of the [[Quran]], placed in [[Nur al-Din Madrasa|the ''madrasa'']] of [[Nur al-Din Zengi|Nur al-Din]] in Damascus]]

Muslim legal experts [[Divisions of the world in Islam|divided the world]] into {{transliteration|ar|Dar al-Islam}} (the [[Muslim world]]) and {{Transliteration|ar|Dar al-harb}} (non-Muslim lands). Border regions like Syria and Iberia became {{transliteration|ar|jihad}} battlegrounds, attracting [[military volunteer]]s—{{transliteration|ar|[[mujahideen]]}} and {{transliteration|ar|[[Ghazi (warrior)|ghazis]]}}—from across {{transliteration|ar|Dar al-Islam}}.{{sfn|Hillenbrand|2018|pp=97–101}}{{sfn|Cobb|2016|pp=9, 33}} Accounts on Christian experiences in the Holy Land on the eve of the Crusades vary.{{refn|group=note|The contemporary Muslim scholar [[Abu Bakr ibn al-Arabi]] did not mention anti-Christian violence, but the 12th-century historian [[al-Azimi]] reported that the "people of the Syrian ports" had obstructed Christian pilgrims from reaching Jerusalem.{{sfn|Asbridge|2012|p=28}}}}{{sfn|Asbridge|2012|p=28}} Attacks on pilgrims likely shaped perceptions of danger,{{sfn|Jotischky|2017|p=40}} though Asbridge highlights that interfaith violence mirrored broader political and social turmoil.{{sfn|Asbridge|2012|pp=28–29}}

Western Christians often mislabelled Muslims as idol-worshippers or heretics.{{refn|group=note|An early example is the popular epic ''[[Song of Roland]]'' ({{circa|1100}}), which depicts the "[[Saracens]]" as a treacherous people worshipping three gods and idols.{{sfn|Ailes|2019|pp=26–27}}}}{{sfn|Jaspert|2006|p=9}}{{sfn|Bull|2002|p=20}} Until {{circa|1110}}, massacres of Muslims in conquered towns were common.{{refn|group=note|One of the earliest examples of mass violence was the [[Siege of Ma'arra|massacre of]] civilians in [[Maarat al-Numan|Ma'arra]], followed by the crusaders' wholesale slaughter of Muslims in Jerusalem after its capture.{{sfn|Tyerman|2007|pp=157–158}}}}{{sfn|Mallett|2020|p=26}}{{sfn|Jotischky|2017|p=137}} Violence was presented as a response to the Muslim occupation of the holy places and the oppression of Christians.{{sfn|Cassidy-Welch|2023|p=51}}

Later, Crusaders rarely sought conversions, instead levying a poll tax akin to the {{Transliteration|ar|jizya}}.{{sfn|Jotischky|2017|pp=137–139}} Church law imposed various restrictions on Muslims, though enforcement is poorly documented.{{refn|group=note|In 1120, the [[Council of Nablus]] issued decrees mandating the castration of Muslim men who had relations with Christian woman, and the mutilation, specifically the cutting of the nose, of Christian women who had slept with Muslim men.{{sfn|Jotischky|2017|p=140}}}}{{sfn|Jotischky|2017|p=140}} In the Crusader states, most Muslims—Arabic-speaking farmers—lived in self-governed communities under [[Islamic law]].{{sfn|Jaspert|2006|p=96}} In Iberia, {{Transliteration|es|[[Mudéjar|mudejares]]}}—Muslims under Christian rule—also faced second-class status.{{sfn|Jaspert|2006|pp=124–125}}{{sfn|Cobb|2016|p=170}}{{sfn|Lock|2006|p=135}}

Initially, few Muslims grasped the Crusades' religious nature. The Damascene scholar [[Ali ibn Tahir al-Sulami]] was the first to frame them as part of broader "[[Farang|Frankish]]", or Westerner, expansion.{{sfn|Jaspert|2006|p=75}}{{sfn|Madden|2013|p=43}} He interpreted their success as divine punishment for neglecting {{transliteration|ar|jihad}}.{{sfn|Cobb|2016|p=39}} Zengi was among the era's first Muslim leaders receiving {{transliteration|ar|jihadist}} honours. Later rulers likewise invoked religious motives in anti-Frankish campaigns.{{sfn|Hillenbrand|2018|pp=111–249}} In Iberia, the [[Almoravids]] and the [[Almohads]] strongly supported {{transliteration|ar|jihad}}.{{sfn|Jaspert|2006|pp=118–121}} Nonetheless, pragmatic Christian–Muslim alliances remained common throughout the period.{{refn|group=note|Viewing the {{Transliteration|ar|jihadist}} efforts of the Seljuq sultan [[Muhammad I Tapar|Muhammad]] as a strategy to extend his dominion, the Muslim rulers of Aleppo and Damascus allied with the Franks of Antioch and Jerusalem to repel a Seljuk invasion in 1115.{{sfn|Jotischky|2017|p=115}}{{sfn|Lock|2006|p=32}} In 1196, [[Alfonso IX of León]] invaded Castile in collaboration with the Almohads, prompting {{nowrap|[[Pope Celestine III]]}} to grant crusade indulgence to those who would take up arms against him.{{sfn|Tyerman|2007|p=666}}}}{{sfn|Jotischky|2017|pp=115, 119, 122}}{{sfn|Cobb|2016|p=64}}

===Eastern Christians===

{{Further|Byzantium in the Crusading movement}}

[[File:Elias IMG 0510.JPG|right|thumb|alt=A bay window on a stone wall|Detail of the Greek Orthodox [[Mar Elias Monastery]] near Bethlehem. Its restoration was financed by the Byzantine emperor [[Manuel I Komnenus]] during the Crusading period.{{sfn|Jotischky|2017|p=154}}]]

The liberation of eastern Christians was declared a central aim of the First Crusade, yet initial encounters proved disappointing.{{sfn|Jotischky|2017|pp=133–134}} Emperor Alexios, anticipating disciplined mercenaries or manageable allies, was unsettled by the Crusaders' influx, and secured oaths guaranteeing the return of reconquered Byzantine lands.{{sfn|Lilie|1993|pp=2–12}} Nonetheless, Bohemond retained Antioch—a former Byzantine provincial capital—for himself.{{sfn|Lilie|1993|pp=40–41}} 

Soon after Antioch's capture, Crusader leaders described local Christians as "heretics" in a letter to Pope Urban.{{sfn|MacEvitt|2008|p=1}} In 1099, Catholic clergy temporalily excluded native clerics from officiating at the Holy Sepulchre.{{refn|group=note|In the Holy Sepulchre, Christ's resurrection had traditionally been commemorated by the lighting of candles from a flame believed by the faithful to descend miraculously from above. Native clergy were readmitted at Eastern 1101, as Catholic priests had failed to sustain the ritual celebration.{{sfn|MacEvitt|2008|p=115}}}}{{sfn|MacEvitt|2008|pp=115–119}} In the Crusader states, Eastern Christians paid a poll tax, signalling their subordinate status, although their self-governance was reinforced{{sfn|Jotischky|2017|p=138}} and some retained considerable landholdings.{{sfn|MacEvitt|2008|pp=144–150}}

Orthodox Christians, or [[Melkites]], formed the majority of Palestine's native Christian population and were also prominent in northern Syria.{{sfn|MacEvitt|2008|p=8}} Regarded as [[Schism in Christianity|schismatics]] rather than heretics, they received limited recognition. Although most Orthodox bishops had fled Palestine before 1099, scattered references suggest the presence of an Orthodox hierarchy under Frankish rule.{{refn|group=note|A notable example is [[Meletos (bishop of Gaza)|Meletos]], the Orthodox bishop of Gaza, who retained his position after the city fell to the Franks in 1149. The historian Christopher MacEvitt attributes this to the Templars, Gaza's new rulers, noting that appointing a Catholic bishop might have provoked disputes over tithes and properties.{{sfn|MacEvitt|2008|pp=112–113}}}}{{sfn|MacEvitt|2008|pp=100, 110–111}} Monasticism experienced a revival under Byzantine patronage.{{sfn|Jotischky|2017|pp=154–155}}

Unlike the Catholics and Orthodox, certain eastern Christian communities rejected the [[Christology]] of the [[Council of Chalcedon]]. Among them, the [[Armenian Apostolic Church|Armenians]]—concentrated in northern Syria and [[Cilicia]]{{sfn|MacEvitt|2008|pp=7–9}}—had their autonomous lordships.{{sfn|Jotischky|2017|p=136}} Many welcomed the Crusaders, and Armenian aristocrats formed marriage alliances with them. This cooperation led to a tenuous [[church union]] with Rome (1198){{sfn|Ghazarian|2005|pp=123–124, 189–190}} and ultimately to the Frankish [[House of Lusignan|Lusignans]]' rule over [[Kingdom of Cilician Armenia|Cilician Armenia]].{{sfn|Lock|2006|pp=378–381}} [[Syriac Orthodox Church|Syriac]] (or Jacobite) Christians, mainly rural and Arabic-speaking, were viewed with suspicion and condescension;{{sfn|Jotischky|2017|p=136}} yet the Jacobite patriarch [[Michael the Syrian]] praised Frankish religious tolerance contrasting it with Byzantine policy.{{sfn|MacEvitt|2008|p=162}} Another distinct group, the [[Maronites]] of [[Mount Lebanon]], entered into communion with Rome, forming the first [[Eastern Catholic Churches|Eastern Rite Catholic Church]] in 1181.{{sfn|MacEvitt|2008|p=9}}

Byzantine–Frankish relations were variable.{{sfn|Lilie|1993|pp=72–73, 168–169, 177, 246–253}} Following the Fourth Crusade, successor states like [[Despotate of Epirus|Epiros]] and [[Empire of Nicaea|Nicaea]] led Greek resistance, although temporary Greek–Frankish alliances were not uncommon.{{refn|group=note|To secure an alliance against Nicaea, the Epirote ruler [[Michael II Komnenos Doukas]] married his daughter [[Anna Komnene Doukaina|Anna]] to [[William of Villehardouin]], the Frankish [[prince of Achaea]] in 1259.{{sfn|Lock|1995|p=83}}}}{{sfn|Lock|1995|pp=80–83}} In [[Frankish Greece]], many Greek {{Transliteration|el|árchontes}} (aristocrats) retained lands and fought alongside Franks. Peasants suffered harsher conditions than under Byzantine rule.{{sfn|Lock|1995|pp=284–288}} Orthodox bishops refusing papal supremacy were replaced by Catholic appointees, but Greek monasteries received papal protection.{{sfn|Lock|1995|pp=205–209, 226–228}} Latin conquest reinforced Orthodox identity, and persistent local resistance ultimately thwarted attempts to church reunification.{{refn|group=note|The final Byzantine emperors, [[John VIII Palaiologos|John VIII]] and [[Constantine XI Palaiologos]], endorsed the church union established at the [[Council of Florence]] in 1439, hoping it would secure Western aid against the Ottomans. However, they were unable to overcome the entrenched opposition of the Byzantine clergy and laity.{{sfn|Tyerman|2019|p=401}}}}{{sfn|Tyerman|2019|pp=399–401}}

In northeastern Europe, Catholic and Orthodox churches coexisted in major trade centres, and the schism did not impede dynastic intermarriage. Catholic missionary activity only intensified after the Fourth Crusade. Despite occasional alliances between Crusaders and [[Kievan Rus'|Rus']] leaders, lasting control over Rus' lands was never achieved.{{sfn|Christiansen|1997|pp=132–137}}

===Pagans===

[[File:Papal bull regarding Lithuanian ruler Mindaugas 1251.jpg|right|thumb|alt=An old manuscript with a large initial letter|[[Pope Innocent IV]]'s [[papal bull]] about the baptism and coronation of the Lithuanian ruler [[Mindaugas]]]]

Trade in raw materials and [[Slavery in medieval Europe|slaves]] had long connected Christian and pagan communities in the [[Baltic region]], although rivalry over trade routes often sparked armed conflict.{{sfn|Christiansen|1997|pp=43–49}} From {{circa|1100}}, intensified [[Ostsiedlung|German colonisation]] and unequal access to resources triggered more frequent clashes between the Wends and their Christian neighbours.{{sfn|Bartlett|1994|p=136}}{{sfn|Christiansen|1997|p=136}} In 1146, while promoting the Second Crusade, the Cistercian abbot [[Bernard of Clairvaux]] encountered Saxon reluctance to abandon anti-Wendish campaigns. Adopting their perspective, he convinced {{nowrap|[[Pope Eugenius III]]}} to proclaim the Wendish Crusade.{{sfn|Asbridge|2012|p=213}}{{sfn|Christiansen|1997|p=5}} The Wends' structured society—with principalities, towns, and a priestly hierarchy—eased their eventual integration into Christendom.{{refn|group=note|The Wendish ruler [[Nyklot]] was the primary target of the 1147 Crusade. His son, [[Pribislav of Mecklenburg|Pribislav]] became the first Christian prince of [[Mecklenburg]] in 1160. Pribislav's son, [[Henry Borwin I, Lord of Mecklenburg|Henry Borwin I]] joined a crusade in the eastern Baltic in 1218, while his grandson [[Henry I, Lord of Mecklenburg|Henry I]] was captured by Muslim forces during a pilgrimage to the Holy Land.{{sfn|Christiansen|1997|p=72}}{{sfn|Bartlett|1994|pp=53–56, 61, 69, 180, 26, 276}}}}{{sfn|Tyerman|2019|p=308}}

Further east, the [[Old Prussians]], [[Latvians]], and [[Curonians]] had long resisted Christianisation. They lived in rural communities led by strongmen who thrived on trade and raiding.{{sfn|Christiansen|1997|pp=36–40}} Crusaders employed coercion, bribery, and promises of protection to gain converts among them;{{sfn|Christiansen|1997|pp=95–101}} and [[papal legate]]s sought to protect these converts from exploitation but achieved little.{{refn|group=note|Under the 1249 [[Treaty of Christburg]], concluded between the papal legate [[Jacques Pantaléon]] and the Teutonic Knights, Christian native lords were formally granted the same rights as their German and Polish counterparts. However, following the Prussian uprisings of 1259 and 1263, the Knights limited these privileges to only the most loyal members of the native aristocracy.{{sfn|Christiansen|1997|pp=130–131}}{{sfn|Tyerman|2019|p=326}}}}{{sfn|Christiansen|1997|pp=130–131}}

The [[Lithuanians]], largely taxpaying peasants under [[Lithuanian nobility|native lords]], unified in the 13th{{nbsp}}century under Grand Prince [[Mindaugas]]. Baptized in 1253, he received a royal crown from [[Pope Innocent IV]] but later reverted to paganism.{{sfn|Christiansen|1997|pp=xiv, 140–176}} In 1386, Grand Prince [[Jogaila]] married Queen [[Jadwiga of Poland]], becoming King Władysław{{nbsp}}II. The subsequent [[Christianization of Lithuania#Christianization by Jogaila and Vytautas|mass conversion of Lithuanians]] to Catholicism eroded the Teutonic Knights' justification for crusade. In 1410, Polish-Lithuanian forces decisively defeated the Knights in the [[Battle of Grunwald]]. The {{Transliteration|de|Preussenreise}} waned, with the last non-German Crusaders entering the Baltic in 1413.{{sfn|Nicholson|2004|p=51}}{{sfn|Christiansen|1997|pp=145, 227–230}}

In the eastern Baltic, Finnic peoples lived in small rural communities, sustained by farming, slave-raiding, and fur-hunting.{{sfn|Christiansen|1997|pp=41–43}} Legend has it that [[Saint Erik|Eric IX of Sweden]] led a [[First Swedish Crusade|crusade to Finland]] in the 1150s, but the earliest confirmed expedition was authorized by [[Pope Gregory IX]] in 1237.{{sfn|Christiansen|1997|pp=113–117}}{{sfn|Lock|2006|p=223}} Danish Crusaders conquered [[Duchy of Estonia (1219–1346)|Estonia]] in 1219, but by mid-century, German knights and burghers dominated the region's politics.{{sfn|Christiansen|1997|pp=199–200}}

===Western dissidents===

[[File:Le massacre des Albigeois.jpg|left|thumb|alt=A miniature depicting knights attacking unarmed people with swords|Crusaders massacre [[Cathars]] at the beginning of the [[Albigensian Crusades]] (a miniature from the late 14th-century {{Transliteration|fr|Chroniques de France ou de St-Denis}}).]]

The Gregorian Reform did not satisfy those seeking a purer, simpler Christianity.{{sfn|Backman|2022|pp=379–381}} [[Commercial revolution|Increased trade]] carried [[Dualism in cosmology|dualist]] ideologies westward. These movements distinguished between an incorruptible God and an evil [[Demiurge#Gnosticism|creator of the material world]]. In Western Europe, their adherents became known as [[Catharism|Cathars]] or Albigensians.{{sfn|Tyerman|2007|pp=568–575}} As Catholic churchmen saw heresy as a fundamental threat to the faith and to salvation,{{sfn|Madden|2013|p=117}} the [[Third Lateran Council]] granted indulgences, in 1179, to those who fought heretics.{{sfn|Tyerman|2019|p=344}} Yet, in southern France, Cathars were deeply embedded in [[Occitania|Occitan]] society, and local elites were unwilling to act against heretical friends or kin.{{sfn|Tyerman|2007|p=575}}

In 1207, Pope Innocent{{nbsp}}III urged [[Raymond VI, Count of Toulouse]], to eradicate heresy. His reluctance or inability to comply led to excommunication by the papal legate [[Peter of Castelnau]], who was soon murdered. In response, Innocent declared a crusade.{{sfn|Jotischky|2017|p=186}}{{sfn|Tyerman|2007|pp=582–584}} Northern French crusaders invaded Occitania, committing atrocities against both Cathars and Catholics.{{refn|group=note|The crusade theorist [[Caesarius of Heisterbach]] claimed that the Cistercian abbot [[Arnaud Amalric]] had urged the Crusaders to kill everybody, stating that "[[Caedite eos. Novit enim Dominus qui sunt eius.|The Lord knows who are his own]]" during the [[Massacre at Béziers]]. In the same town, prelates called the slaughter of {{circa}} 20,000 people as a miracle.{{sfn|Tyerman|2007|pp=480, 591, 962 (note 59)}}}}{{sfn|Jotischky|2017|pp=186–187}} Though the campaigns strengthened French influence, they failed to eliminate heresy. That was eventually achieved by [[Mendicant orders|mendicant friars]], [[inquisitor]]s and secular authorities.{{sfn|Jaspert|2006|p=137}}

The [[Stedinger Crusade]] in northern Germany targeted peasants accused of heresy for refusing to pay the [[tithe]] (church tax).{{sfn|Jaspert|2006|p=142}} Hungarian rulers led [[Bosnian Crusade|two failed crusades]] into [[Banate of Bosnia|Bosnia]], allegedly home to a Cathar [[antipope]].{{sfn|Lock|2006|p=172}} In contrast, the radical {{Transliteration|it|[[Apostolic Brethren|Apostolici]]}} in northern Italy were swiftly crushed by crusading forces.{{sfn|Jaspert|2006|p=138}}

===Mongols===

[[File:BitvaULehnice.jpg|left|thumb|alt=A drawing depicting horsemen holding spears, with a severed head on one of the spears, at the gates of a fortress defended by arrowmen|Mongols displaying the severed head of the Silesian prince [[Henry II the Pious|Henry the Pious]] after the [[Battle of Legnica]] (from a mid-15th-century ''Legend'' of his mother [[Hedwig of Silesia|St Hedwig]])]]

In 1206, Temüjin was proclaimed [[Genghis Khan]], uniting the Mongol tribes under the belief in a [[Tengri|divine]] destiny to conquer the world.{{sfn|Mayer|2009|pp=267–268}} Western Europeans first learned of the [[Mongol conquest of Central Asia|earliest Mongol conquests]] during the Fifth Crusade.{{sfn|Tyerman|2007|p=641}} As some tribes followed the [[Church of the East|Eastern Syriac]] (Nestorian) Church, fragmentary reports of Mongol advances revived legends of [[Prester John]], a mythical Eastern Christian ruler viewed as a potential ally against Islam.{{sfn|Jotischky|2017|p=257}}{{sfn|Madden|2013|p=165}} However, the [[Mongol invasion of Europe|Mongol invasion of Eastern and Central Europe]] in 1239–42 shocked Western Christendom. Although Pope Gregory{{nbsp}}IX called for a crusade, the Mongols withdrew from Europe following the death of [[Ögedei Khan]], Genghis's successor, in 1242.{{sfn|Lock|2006|p=176}}{{sfn|Mayer|2009|p=269}}

In the Middle East, Mongol forces [[Siege of Baghdad|sacked Baghdad]] and destroyed the Abbasid Caliphate in 1258. Seeking protection, [[Hethum I|Hethum I of Cilician Armenia]] and [[Bohemond VI of Antioch]] submitted to [[Hulegu]], the Mongol {{Transliteration|mn|[[il khan]]}} (ruler of the Middle East). The [[Ilkhanate]]'s expansion ended in 1260 when Mamluk forces defeated Hulegu's army in the [[Battle of Ain Jalut]].{{sfn|Jotischky|2017|pp=257–258}}

===Jews===

{{Main|History of the Jews and the Crusades}}
{{See also|Blood libel}}

Roman legislation under [[Constantine the Great]], the first Christian emperor, and Augustine's theology shaped Western Christian views of [[Judaism]]. Constantine [[History of the Jews in the Roman Empire|upheld Judaism's legality]] but imposed restrictions on its practitioners; Augustine asserted that Jews were divinely preserved yet punished with [[Jewish diaspora|dispersion]] for rejecting Jesus.{{sfn|Chazan|2006|pp=27–38}} 

Jewish migration to Western Europe coincided with the pre-Crusade economic boom.{{sfn|Lock|2006|p=397}} Coming from developed Islamic economies, Jewish merchants brought advanced commercial expertise. Free from canon law's anti-[[usury]] rules, they came to dominate moneylending, fuelling [[Medieval antisemitism|antisemitism]].{{sfn|Chazan|2006|pp=217–219}} Local rulers valued Jewish economic contributions and offered protection, though often fragile.{{sfn|Lock|2006|p=397}}

Organized pogroms began [[Rhineland massacres|in the Rhineland]] during the First Crusade, reportedly driven by vengeance [[Jewish deicide|for Christ's death]] and desire for Jewish property.{{sfn|Tyerman|2019|pp=80–81}}{{sfn|Lock|2006|pp=397–398}} In Jerusalem, Crusaders massacred Jews,{{sfn|Lock|2006|p=399}} though communities in other towns—such as [[Tyre, Lebanon|Tyre]] and [[Ascalon]]—survived. Jewish pilgrimage to the Holy Land intensified, with hundreds of western Jews settling there during the Crusades era.{{sfn|Jaspert|2006|pp=98–99}} Although [[Pope Calixtus II]]'s bull {{transliteration|la|Sicut Iudeis}} forbade violence against Jews, crusade preaching repeatedly incited antisemitic pogroms.{{sfn|Cassidy-Welch|2023|p=49}}{{sfn|Lock|2006|pp=400–401}}{{sfn|Tyerman|2019|p=82}}

==Women==

{{Main|Women in the Crusades}}

[[File:Ida syni.jpg|left|thumb|alt=A lady and an armed horseman embracing each other and a group of marching horsemen|[[Ida of Lorraine]]'s farewell to her sons [[Godfrey of Bouillon|Godfrey]] and [[Baldwin I of Jerusalem|Baldwin of Boulogne]] departing for the [[First Crusade]] (a miniature from a 13th-century manuscript of the {{Transliteration|fr|[[Roman d'Alexandre]]}})]]

Women were involved in the crusading movement from the outset.{{sfn|Tyerman|2019|p=10}} Though popes discouraged female participation, women always accompanied the armies as servants.{{sfn|Madden|2013|p=132}} [[Washerwoman|Washerwomen]] received special papal approval early on.{{sfn|Caspi-Reisfeld|2001|p=96}} Women needed permission from a father or husband to join a crusade, whereas men, from 1209, could go without their wives' consent.{{sfn|Tyerman|2019|pp=10–12}} 

Gender bias prevailed on all sides.{{sfn|Lock|2006|p=343}} Christian chroniclers highlighted women's supportive roles—delivering water or stone missiles—but rarely mentioned female fighters.{{sfn|Caspi-Reisfeld|2001|pp=97–100}} Muslim and Byzantine writers, in contrast, often depicted armed Crusader women as symbols of barbarity.{{sfn|Lock|2006|pp=343–344}} Muslim sources also condemned the freedoms women enjoyed in Frankish societies.{{sfn|Madden|2013|pp=45–46}} Crusaders were expected to abstain from sex; and women, both wives and sex-workers, were often expelled before major battles.{{sfn|Hodgson|2017|p=138}}{{sfn|Madden|2013|p=132}} Occasionally, high-ranking women led troops or conducted key diplomatic negotiations.{{refn|group=note|The widowed Austrian margravine [[Ida of Austria|Ida]] commanded her own army, and disappeared in the Battle of Heraclea in 1101. In Iberia, [[Ermengarde, Viscountess of Narbonne|Ermengarde of Narbonne]] led a contingent during the siege of Tortosa in 1148. During the [[Seventh Crusade]], [[Margaret of Provence]] led the negotiations about the ransom of her husband [[Louis IX of France]] with the Egyptian sultana [[Shajar al-Durr]].{{sfn|Hodgson|2017|pp=49, 118, 211–212}}{{sfn|Tyerman|2019|pp=10–12}}}}{{sfn|Tyerman|2019|pp=10–12}}

Women left behind were vulnerable to abuse by kin or neighbours.{{refn|group=note|The wife of the English crusader William Trussel was murdered and her body was profaned shortly after he had left for the Third Crusade. The only daughter of an other English crusader Ralph Hodeng married to one of his tenants during his absence.{{sfn|Riley-Smith|2002a|p=74}}}} Some Crusaders made formal arrangements with relatives or religious institutions to protect their wives and daughters; others entrusted wives or mothers with managing their estates.{{refn|group=note|In France, female regency was quite common: both Philip{{nbsp}}II and Louis{{nbsp}}IX appointed their mothers—[[Adela of Champagne]] and [[Blanche of Castile]], respectively—to rule during their absence. On the other hand, Louis charged two men [[Simon of Nesle]] and [[Matthew of Vendôme (abbot)|Matthew of Vendôme]] to govern his kingdom during his second crusade instead of his wife, Margaret of Provence.{{sfn|Hodgson|2017|pp=176–177}}}}{{sfn|Riley-Smith|2002a|pp=73–75}} Raids by both Christian and Muslim forces frequently targeted women. After battles or sieges, victors often captured enemy women and children.{{sfn|Friedman|2001|p=121}} The First Crusade was exceptional: crusaders often massacred entire populations of captured towns.{{sfn|Friedman|2001|pp=127–128}} In the Baltic, the ''[[Livonian Rhymed Chronicle]]'' praised the slaughter of pagan women and children as divinely sanctioned.{{sfn|Christiansen|1997|pp=95–96}} [[Wartime sexual violence|Rape]] of captured women both by crusaders and their enemies was common.{{sfn|Hodgson|2017|p=96}}{{sfn|Friedman|2001|p=126}} Noblewomen were typically ransomed, albeit for less than men of the same rank; other women were enslaved or forced into marriage.{{sfn|Friedman|2001|pp=124–133}}

High male mortality in the Crusader states meant that women often inherited fiefs, though they were expected to marry.{{sfn|Hodgson|2017|p=73}} Some inherited thrones: between 1186 and 1228, for example, four queens ruled Jerusalem.{{refn|group=note|[[Sibylla, Queen of Jerusalem|Sibylla]] ({{reign|1186|1190}}), her sister [[Isabella I of Jerusalem|Isabella I]] ({{reign|1192|1205}}), Isabella's daughter [[Maria of Montferrat|Maria]] ({{reign|1205|1212}}), and Maria's daughter [[Isabella II of Jerusalem|Isabella II]] ({{reign|1212|1228}}).{{sfn|Tyerman|2019|p=476}}{{sfn|Lock|2006|pp=484–485}}}}{{sfn|Hodgson|2017|p=77}} In Frankish Greece, the wives of [[Principality of Achaea|Achaean]] barons captured at the [[Battle of Pelagonia]] formed the "[[Parliament of Dames]]" in 1261 to negotiate peace with the Byzantines.{{sfn|Lock|1995|pp=303, 305}}

==Crusading in practice==

Tyerman notes that crusading "paraded across society in recruitment, funding and social rituals of support". The movement was accompanied by [[Procession#Christian practice|processions]], priestly blessings, charity, and artifacts.{{sfn|Tyerman|2019|p=8}} 

===Declaration and promotion===
{{Main|Crusade bull|Crusade preaching}}
Crusades were typically proclaimed by the pope in his capacity as [[Vicar of Christ]].{{sfn|Riley-Smith|2005|p=128}} [[Crusade bull]]s articulated the aims, urged participation, and detailed spiritual and temporal rewards,{{refn|group=note|The 1145 papal bull {{Transliteration|la|[[Quantum praedecessores]]}} provided the template for subsequent [[Encyclical#Catholic usage|encyclicals]].{{sfn|Housley|2002|p=42}}}}{{sfn|Housley|2002|p=42}}{{sfn|Nicholson|2004|pp=xlvi–xlvii}} and were read in all Catholic churches from [[Pope Alexander III]]'s time.{{sfn|Housley|2002|p=43}} Pope Gregory{{nbsp}}IX authorized the [[Dominican Order|Dominicans]] to preach Baltic crusades without further approval,{{sfn|Christiansen|1997|p=83}} a privilege later extended to the [[Franciscans]] and Teutonic clergy.{{sfn|Tyerman|2007|p=705}} 

{{Quote box
 |title     = Excerpts from the papal bull proclaiming the Third Crusade (1187)
 |quote     = We have heard and tremble at the severity of the judgment that the Divine hand has executed over the land of Jerusalem. ... Because of some disagreement that came about in that country through human malice from diabolical instigation, Saladin entered that area with a great many armed men ..., and our side was overcome, the Lord's Cross was captured...
 |author    = [[Pope Gregory VIII]]
 |source    = {{transliteration|la|[[Audita tremendi]]}}{{sfn|Nicholson|2004|p=141}}
 |align     = center
 |width     = 66.6%
 |bgcolor   = #F5FAFF
 |title_bg  = #CEE0F2
 |qalign    = left
 |salign    = right
 }}

Crusades were promoted by clerics. Papal legates addressed nobles at major assemblies. Village and town preaching was unstructured until Pope Innocent{{nbsp}}III coordinated propaganda through local committees, though subsequent popes preferred less formal methods. From the early 13th{{nbsp}}century, mendicant friars assumed responsibility for preaching. By the century's end, many used manuals by propagandists like [[Humbert of Romans]].{{sfn|Housley|2002|pp=43–45}} Crusade-promotional sermons often began with [[Exemplum|moral anecdote]]s.{{sfn|Jaspert|2006|p=67}}

===Taking the cross===
{{main|Crusade vow}}
Crusaders took public vows, usually followed by a ceremony where a cloth or silk cross—typically red—was sewn onto their cloak. By "taking the cross", they pledged to follow [[Matthew 16:24|Christ's call]]: "If any man will come after me, let him deny himself and take up his cross and follow me".{{sfn|Riley-Smith|2002a|p=69}}{{sfn|Tyerman|2019|pp=4–5}} This reflected the 11th-century {{Transliteration|la|[[Imitation of Christ|imitatio Christi]]}} ("imitation of Christ") movement.{{sfn|Jaspert|2006|p=29}} Pilgrim emblems like a staff and a pouch were often also distributed.{{sfn|Riley-Smith|2002a|pp=691}} The cross had to be worn by crusaders until their return; premature removal was sanctioned by church authorities,{{refn|group=note|The excommunication of Emperor Frederick{{nbsp}}II serves as a telling example. In 1227, he embarked on a crusade, but an outbreak forced him to return. Nevertheless, Pope Gregory{{nbsp}}IX excommunicated him for failing to fulfill his vow. Jotischky argues that Frederick's efforts to consolidate his authority over the Church in Sicily may have been the true cause of his excommunication.{{sfn|Jotischky|2017|pp=237–238}}}}{{sfn|Riley-Smith|2002a|p=71}} with rare exceptions like illness, poverty, or incapacity.{{sfn|Lloyd|2002|p=48}} By the late 12th{{nbsp}}century, crusaders were widely known as {{transliteration|la|crucesignati}} ("signed with the cross").{{sfn|Tyerman|2019|p=5}}

===Privileges===

As penitents and armed pilgrims, Crusaders were classed in canon law as provisional clerics under ecclesiastical jurisdiction.{{sfn|Riley-Smith|2005|p=128}} Their early secular privileges are poorly documented. According to a [[Codex Laurentianus|collection of]] canon law, First Crusaders and their goods were "under the Truce of God". Guibert of Nogent notes that Pope Urban extended protection to crusaders and their households.{{sfn|Brundage|1997|pp=141–143}} In 1107, the canonist [[Ivo of Chartres]] still called this legal treatment "new".{{refn|group=note|{{nowrap|[[Pope Paschal II]]}} had instructed Ivo to excommunicate the French nobleman [[Rotrou III, Count of Perche]] for constructing a fort on the land belonging to the crusader [[Hugh I of Jaffa|Hugh II of Le Puiset]]. However, Ivo hesitated, stating he did not "wish to punish, like some assassin, without a hearing".{{sfn|Brundage|1997|pp=144–145}}}}{{sfn|Riley-Smith|2002a|pp=71–72}} The First Lateran Council formalized it, protecting the crusaders' "houses and households" and ordering {{transliteration|la|[[Latae sententiae and ferendae sententiae|latae sententiae]]}} or automatic excommunication for infractions, but enforcement was inconsistent.{{sfn|Brundage|1997|pp=146-147, 152–153}} Pope Eugenius{{nbsp}}III also suspended lawsuits against crusaders and interest payment on their debts,{{sfn|Jaspert|2006|p=64}}{{sfn|Brundage|1997|p=147}} and authorised them to sell land—including fiefs—without the consent of family members or lords.{{sfn|Blaydes|Paik|2016|p=558}}

===Finances===

[[File:Innozenz3.jpg|right|thumb|alt=A middle-aged man wearing a papal triara|[[Pope Innocent III]]: by sanctioning the redemption of crusading vows for cash, he created a massive new source of income for crusading (a fresco in St. Benedict's Cave at the [[Subiaco Abbey]], {{circa|1219}})]]

The historian Simon Lloyd notes that crusading was "crippingly expensive". Although precise figures are mainly lacking,{{refn|group=note|The first crusade of [[Louis IX of France]] stands out as a notable exception: between 1248 and 1254, he spent 1,537,570 {{Transliteration|fr|[[livre tournois|livres tournois]]}}—over 600{{nbsp}}percent of his average annual income—on his campaigns in the Levant. In addition to financing his own expedition, he also supported his companions through gifts and loans, leading Lloyd to estimate Louis's total expenditure at {{circa|3,000,000}} {{Transliteration|fr|livres}}. Yet even this substantial sum excludes expenses incurred by other crusaders who joined his campaign.{{sfn|Lloyd|2002|p=53}}}}{{sfn|Lloyd|2002|p=53}} estimates suggest that a knight spent over four years' income.{{sfn|Phillips|2014|p=24}} Aristocrats sold commodities or granted civic privileges for cash.{{refn|group=note|Before departing on his crusade in 1236, Earl [[Richard of Cornwall]] ordered entire woodlands to be felled in order to sell timber. In 1202, [[Hugh IV, Count of Saint-Pol]], granted urban privileges to three or four settlements within his domains.{{sfn|Lloyd|2002|p=55}}}} Inherited lands were often mortgaged or pledged via [[vifgage]], allowing creditors repayment from property income. Others secured funds through gifts or loans from kin or lords.{{refn|group=note|For instance, Duke [[Robert Curthose]] pledged [[Duchy of Normandy|Normandy]] to his brother, [[William Rufus]], King of England, as a security for a loan of 10,000{{nbsp}}marks in 1096.{{sfn|Mayer|2009|p=44}}}}{{sfn|Lloyd|2002|pp=54–56}} In Iberia, {{transliteration|es|[[parias]]}} (tributes from Muslim rulers) helped fund Christian forces.{{sfn|O'Callaghan|2003|p=127}}

An extraordinary tax for Holy Land defence was first introduced in France and England in 1166. The 1188 "[[Saladin tithe]]" imposed a ten{{nbsp}}percent levy on income and property, though [[tax noncompliance|compliance]] varied.{{sfn|Lloyd|2002|pp=56–57}} In 1199, Pope Innocent{{nbsp}}III ordered [[Papal income tax|church revenues taxed]] for crusading. [[Pope Gregory X]] defined collection procedures in 1274, but clergy often resisted.{{sfn|Jotischky|2017|p=269}}{{sfn|Lloyd|2002|pp=57–58}}

From 1199, donations were gathered via [[Chest (furniture)|church chests]].{{sfn|Lloyd|2002|p=58}} In 1213, Innocent{{nbsp}}III introduced a new mechanism, allowing anyone—except monks—to vow a crusade and redeem it financially.{{sfn|Lloyd|2002|pp=48, 58}}{{sfn|Tyerman|2019|p=238}} This practice of purchasing indulgences continued into the early modern period.{{refn|group=note|In Germany, an indulgence cost roughly the equivalent of a household's weekly expenses {{circa|1500}}.{{sfn|Tyerman|2019|p=425}}}} With the spread of printing in the mid-15th{{nbsp}}century, indulgence sheets were mass-produced with blanks for beneficiaries' names.{{sfn|Tyerman|2019|p=425}}

==Warfare==

{{Main|Crusading warfare}}

The historian Peter Lock notes that launching "a crusade was no easy task and the time given for preparation was often short". The gathering of pack animals, wagons, war horses, and supplies, like fodder and water, was essential in individual crusades' success, but is poorly documented in contemporary sources.{{sfn|Lock|2006|pp=323, 325}}

===Command, strategy and troops===

{{See also|Passagium}}

Command during most crusades was divided and uncertain, with desertion common.{{sfn|France|1999|pp=208–210}} Still, morale was often sustained by [[Vision (spirituality)|visions]], processions, and [[relics]].{{refn|group=note|Between 1099 and 1187, the Jerusalemite army carried the [[True Cross]]—a relic linked to Christ's crucifixion—into 31{{nbsp}}battles.{{sfn|Phillips|2014|pp=142–143}}}}{{sfn|Phillips|2014|pp=142–143}}{{sfn|Tyerman|2019|pp=92–93}} Most Crusaders lacked experience in urban sieges, which were typical of Levantine warfare.{{sfn|Phillips|2014|p=96}} Crusaders generally avoided [[pitched battle]]s in which defeat risked catastrophic losses.{{refn|group=note|The Franks suffered catastrophic defeats [[Battle of Harran|at Harran]] (1104), [[Battle of the Field of Blood|on the Field of Blood]] (1119), and [[Battle of Harim|at Harim]] (1164) in Syria, and [[Battle of Pelagonia|at Pelagonia]] (1259) and [[Battle of Halmyros|at Halmyros]] (1311) in Frankish Greece.{{sfn|Phillips|2014|p=97}}{{sfn|Lock|1995|pp=91, 106}} In the north, the Lithuanians' victory over the Sword Brothers [[Battle of Saule|at Saule]] annihilated the Brothers' power.{{sfn|Christiansen|1997|p=102}}}}{{sfn|Phillips|2014|p=97}} Siege warfare used [[trebuchet]]s, [[siege tower|towers]], and [[battering ram]]s. Muslim defenders employed [[Greek fire]], countered by crusaders with vinegar-soaked [[Hide (skin)|hides]].{{sfn|Phillips|2014|pp=105–106}} From the late 13th{{nbsp}}century, strategic planning for Holy Land campaigns distinguished between an initial campaign ({{transliteration|la|passagium particulare}}) to secure a foothold and the full-scale {{transliteration|la|passagium generale}}.{{sfn|Tyerman|2019|p=379}}

Heavily armoured knights formed the Crusader armies' backbone.{{sfn|Phillips|2014|p=98}} The historian John France calls them the "masters of close-quarter warfare". In the east, they primarily confronted mounted archers and relied on infantry, particularly bowmen and spearmen, for support.{{sfn|France|1999|p=219}} Franks also employed native light cavalry, or [[Turcopole]]s, to harass enemy troops.{{sfn|France|1999|pp=219–220}} In the north, Teutonic Knights deployed converted Prussians for raids on pagan settlements.{{sfn|Christiansen|1997|p=100}} Spanish [[almogavars]]—agile raiders—fought with daggers, short lances, and [[Dart (missile)|darts]].{{sfn|O'Callaghan|2003|p=129}}

Naval support came mainly from Italian city-states and the Byzantines in the Levant. Egypt maintained the sole Muslim fleet in the region, but its small vessels posed little threat to Western dominance. After Emperor Frederick{{nbsp}}I's failed overland expedition, major Levantine crusades were done by sea.{{sfn|France|1999|p=207}} In the north, large Christian merchant ships, carrying up to 500{{nbsp}}people, easily outmatched Baltic long-ships and raiding vessels.{{sfn|Christiansen|1997|p=91}}

===Military architecture===

{{See also|List of Crusader castles}}

Throughout conquered territories, castles served military and administrative functions, merging Western and local designs. In the Levant, early Norman-style towers gave way to the local {{Transliteration|la|[[castra]]}} layout of walled courtyards, which evolved into concentric castles with layered defences.{{refn|group=note|[[Montreal (castle)|Montreal Castle]], built in 1115, represents the earliest instance of the Franks adapting the local {{Transliteration|la|castra}} form. The concentric castle design was implemented later, with the construction of [[Belvoir Castle (Israel)|Belvoir Castle]] in 1168.{{sfn|Tyerman|2019|pp=142–143}}}}{{sfn|Tyerman|2019|p=142}}{{sfn|Phillips|2014|pp=104–105}} [[Spur castle]]s on rocky hills, with towers and a keep, represent—according to Phillips—"the most spectacular examples of Frankish military architecture".{{refn|group=note|[[Saone Castle]] in the Principality of Antioch, [[Kerak Castle]] in the Kingdom of Jerusalem, and [[Crac des Chevaliers]] in the County of Tripoli are among the best known examples of spur castles.{{sfn|Phillips|2014|pp=104–105}}}}{{sfn|Phillips|2014|p=104}} In Iberia, over 2,000{{nbsp}}castles were raised along frontiers.{{sfn|O'Callaghan|2003|pp=124–125}} The Teutonic Knights first built timber [[blockhouse]]s in the Baltic, but by {{circa|1250}} switched to stone, then brick for its availability and lower cost.{{sfn|Christiansen|1997|pp=67}}

===Military orders===

{{Main|Military order (religious society)}}

[[File:SCONTRO A NABLUS - AFFRESCHI CONTROFACCIATA S. BEVIGNATE.JPG|thumb|left|alt=Fresco from San Bevignate showing men on horseback fighting |[[Templars]] battling Muslim warriors (late 13th-century [[fresco]] from [[San Bevignate]])]]

Tyerman argues that the [[Military order (religious society)|military orders]] were "crusading's most original contribution to the institutions of medieval Christendom". These [[Religious order (Catholic)|religious communities]] followed [[monastic rules]] but were committed to armed defence of Christianity.{{sfn|Tyerman|2019|pp=151–152}}{{sfn|Forey|2002|pp=176–177}} The first emerged when the French noble [[Hugues de Payens]] and fellow knights pledged to protect pilgrims in the Holy Land. Taking the [[Consecrated life|monastic vows]] of chastity, poverty, and obedience in 1119, they formed a confraternity. They became known as the [[Knights Templar]] after their headquarters in the former [[Al-Aqsa Mosque]], associated with the [[Temple of Solomon]].{{sfn|Madden|2013|p=46}}{{sfn|Tyerman|2019|pp=152–154}}

The idea of warrior-monks aligned with contemporary chivalric and ecclesiastical ideals.{{sfn|Phillips|2014|p=67}} By {{circa|1130}}, Bernard of Clairvaux praised the Templars as a "new knighthood".{{sfn|Tyerman|2019|p=154}} Their model inspired other groups, especially in borderlands of Latin Christianity.{{sfn|Forey|2002|p=178}} In the Holy Land, nursing confraternities became militarized, giving rise to orders such as the [[Knights Hospitaller]], Teutonic Knights, [[Knights of Saint Thomas]], and [[Order of Saint Lazarus|Lazarists]].{{sfn|Tyerman|2019|pp=154–156}}{{sfn|Forey|2002|p=178}} In Iberia, royal patronage supported orders, such as [[Order of Calatrava|Calatrava]], [[Order of Santiago|Santiago]], [[Order of Alcántara|Alcántara]], and [[Military Order of Aviz|Aviz]]. In the Baltic, bishops founded the Sword Brothers and the [[Order of Dobrzyń]], both later absorbed by the Teutonic Order.{{sfn|Jaspert|2006|pp=148–150}}{{sfn|Forey|2002|pp=179–180}}

Military orders were structured by function: knight-[[Religious brother|brothers]] and {{lang|la|servientes}} (military servants} fought; priest-brothers provided spiritual care; nobles could temporarily join for spiritual rewards.{{sfn|Jaspert|2006|pp=155–156}} The Templars and Hospitallers grew into transnational institutions, led by elected [[Grand master (order)|grand masters]] and owning estates throughout Western Christendom.{{sfn|Jotischky|2017|pp=83–90}}{{sfn|Jaspert|2006|p=157}} Their convent networks facilitated the flow of goods and cash.{{sfn|Forey|2002|pp=191–192}} 

The orders were occasionally criticized for greed, pride, or adopting non-Christian customs.{{sfn|Jaspert|2006|p=162}} After the Crusader states fell, criticism increased because many orders lost their justification for existence. The Templars, focused solely on fighting Muslims, faced intense scrutiny.{{sfn|Jaspert|2006|pp=162–163}} In 1307, [[Philip IV of France]] ordered [[Trials of the Knights Templar|their mass arrest]] on charges of [[Apostasy in Christianity|apostasy]], idolatry, and [[sodomy]]. Despite the lack of physical evidence, the Order was dissolved at the [[Council of Vienne]] in 1312.{{sfn|Forey|2002|pp=208–210}} The Hospitallers endured but shifted focus to naval defence in the Mediterranean. In Iberia, the military orders gradually secularized, aligning with the crown of Spain and Portugal. The Teutonic Knights survived the Reformation under [[Habsburgs|Habsburg]] leadership in Germany.{{sfn|Luttrell|2002|pp=333–338, 344–345, 350–358}}

==New states==

The crusading movement fostered the creation of new states on the fringes of Latin Christendom. The historian [[Robert Bartlett (historian)|Robert Bartlett]] describes these states as "autonomous replicas, not dependencies, of western and central European polities".{{sfn|Bartlett|1994|pp=308–309}}

===Crusader states and Cyprus===

{{Main|Crusader states|Kingdom of Cyprus}}

The four Crusader states established Catholic rule in the Levant{{sfn|Jotischky|2017|p=83}} and strengthened commercial links between the region and Catholic Europe.{{sfn|Blaydes|Paik|2016|p=561}} Their limited economic surpluses were directed chiefly towards military needs.{{sfn|Tibble|2025|p=16}} Edessa, the earliest and weakest, fell after a failed alliance with Zengi's Muslim rivals, the [[Artuqids]].{{sfn|Jotischky|2017|p=83}} Internal strife undermined Jerusalem, leaving it vulnerable to Saladin's conquest, though the Third Crusade regained much of the coast. Antioch and Tripoli entered union after [[War of the Antiochene Succession|a succession war]].{{sfn|Phillips|2002|p=135}} After Frederick{{nbsp}}II's Crusade, absentee monarchs left Jerusalem under regents, sometimes chosen by their opponents.{{sfn|Jaspert|2006|p=88}} By the Mamluk advance, the Frankish East had fragmented into competing lordships and [[Medieval commune|communes]].{{sfn|Jaspert|2006|pp=94–95}}

Cyprus, a day's sail from Syria, was a vital crusading base and refuge.{{sfn|Phillips|2002|pp=125–129}} From 1269, its kings claimed Jerusalem, although the [[Capetian House of Anjou|Sicilian Angevins]] contested this from 1277.{{sfn|Lock|2006|pp=116, 119}} The [[Black Death]] and shifting trade routes led to decline {{circa|1350}}. A Cypriot [[Alexandrian Crusade|Crusade on Alexandria]] provoked Genoese reprisals, leading to the sack of the main port of Cyprus, [[Famagusta]]. After the Lusignan dynasty ended in 1474, the island [[Venetian Cyprus|passed to Venice]].{{sfn|Edbury|2002|pp=294–298}}

===Frankish Greece===

{{Main|Frankokratia}}

Months before the sack of Constantinople, the leaders of the Fourth Crusade agreed to [[Partitio terrarum imperii Romaniae|partition the Byzantine Empire]]: an elected emperor would receive a quarter, the rest go to other Frankish leaders and Venice.{{sfn|Jotischky|2017|p=182}}{{sfn|Phillips|2002|p=129}} More stable than the Crusader states, Frankish Greece attracted more Western settlers.{{sfn|Phillips|2002|p=129}} Demand for wheat, olive oil, and silk enriched the lords of the [[Peloponnese]] in Greece, turning the court of the [[Villehardouin family|Villehardouin]] princes of Achaea into a centre of chivalric life.{{sfn|Phillips|2002|p=131}}{{sfn|Jotischky|2017|p=226}} [[Treaty of Viterbo|Under Angevin protection]], Achaea survived the Byzantine revival until the [[Despotate of the Morea]] annexed it in 1430. Achaea's former vassal, the [[Duchy of Athens]], was first [[Battle of Halmyros|seized by]] mutinous [[Catalan Company|Catalan mercenaries]], and later by the [[Acciaioli family|Acciaioli]], a Florentine banking dynasty, but fell to the Ottomans in 1460.{{sfn|Edbury|2002|pp=299–304}} Despite [[Ottoman–Venetian wars|Ottoman pressure]], Venice retained parts of [[Stato da Màr|its overseas empire]] into the 18th{{nbsp}}century.{{sfn|Edbury|2002|pp=307–310}}

===Order states===

{{Main|State of the Teutonic Order|Hospitaller Rhodes|Hospitaller Malta}}

The Teutonic Order was granted [[Kulmerland]] in Prussia by [[Konrad I of Masovia|a Polish duke]] in the 1220s, soon gaining autonomy over future conquests. In 1237, the Teutonic Knights seized Livonia through merger with the Sword Brothers.{{sfn|Christiansen|1997|pp=82–83, 103}} After the Crusader states fell, the Order focused on the Baltic,{{sfn|Forey|2002|p=208}} attracting German settlers with land and privileges. After the Battle of Grunwald, Polish incursions, and [[Prussian Confederation|internal strife]] weakened its control, and by 1438, Livonia acted independently.{{sfn|Luttrell|2002|pp=333, 343}} [[Duchy of Prussia|Prussia]] became a Protestant duchy in 1525, [[Duchy of Courland and Semigallia|Livonia]] in 1561.{{sfn|Christiansen|1997|pp=246–247, 257}}

The Hospitallers captured the island of [[Rhodes]] from the Byzantines in 1306–1309.{{sfn|Edbury|2002|p=298}} Despite its strong fortifications and earlier resistance to Mamluk and Ottoman assaults, Rhodes was [[Siege of Rhodes (1522)|taken]] by Sultan [[Suleiman the Magnificent|Suleiman{{nbsp}}II]] in 1522.{{sfn|Luttrell|2002|p=334}}{{sfn|Edbury|2002|p=299}} In 1530, Emperor [[Charles V, Holy Roman Emperor|Charles{{nbsp}}V]] granted the Hospitallers the islands of [[Malta (island)|Malta]] and [[Gozo]].{{sfn|Luttrell|2002|p=347}} They withstood the 1565 [[Great Siege of Malta]], but lost the islands to [[Napoleon Bonaparte]] in 1798.{{sfn|Luttrell|2002|pp=348, 356–357}}

==Criticism==

{{Main|Criticism of crusading}}

[[File:Ninety-Five Theses WDL7497.png|thumb|right|alt=A paper with printed text|[[Martin Luther]]'s ''[[Ninety-five Theses]]'' against indulgences (1517)]]

Opponents of the Gregorian Reform, such as [[Sigebert of Gembloux]], condemned penitential warfare, but their voice was lost in the euphoria following the First Crusade.{{sfn|Riley-Smith|2002a|pp=79–80}} The concept was equally alien to Byzantines; Princess [[Anna Komnene]] openly scorned the Crusades and their participants.{{sfn|Dennis|2001|pp=33, 39}} Mainstream Catholic criticism targeted specific aspects such as the risks posed by crusaders' absences.{{sfn|Jaspert|2006|p=69}} The rise of military orders also drew objections from those who viewed monasticism as incompatible with knighthood.{{sfn|Phillips|2014|p=71}} [[Millenarianism|Millenarian]] thinkers like [[Joachim of Fiore]] saw the Crusades as transient, predicting the Muslims' voluntarily conversion.{{sfn|Jaspert|2006|p=71}}

As the Crusades spread geographically, criticism intensified, especially over campaigns against Christians for diverting focus from the Holy Land.{{refn|group=note|[[Guilhem Figueira]], a famous [[troubadour]], blamed the papacy for the failure of the Fifth Crusade at Damietta, stating that the Holy See had offered a "false pardon" to the French crusaders when declaring the Albigensian Crusades.{{sfn|Routledge|2002|p=109}}}}{{sfn|Jaspert|2006|p=69}} Some Occitan [[troubadour]]s even equated anti-heretic crusaders with Muslim foes.{{sfn|Routledge|2002|pp=108–109}} The Levantine crusades' failure prompted the chronicler [[Salimbene di Adam]] to conclude they lacked divine support.{{sfn|Jaspert|2006|p=69}} Driven by despair, the troubadour [[Austorc d'Aorlhac]] and the Templar [[Ricaut Bonomel]] approached apostasy in their lyrics.{{sfn|Paterson|2019|pp=49–50}} In 1274, Humbert of Romans produced a full rebuttal to anti-Crusade critics.{{sfn|Jaspert|2006|p=70}}

From the Reformation, anti-Catholic theologians attacked crusading.{{sfn|Housley|2002|pp=285–286}} [[Martin Luther]] denounced indulgences and papal authority.{{sfn|Thomson|1998|p=203}} The Catholic theologian [[Erasmus]] also criticized indulgence preaching and clerical involvement in warfare.{{sfn|Housley|2002|pp=286–287}}

{{Quote box
 |title     = Excerpts from Martin Luther's first thesis against indulgences (1517)
 |quote     = Although indulgences are the very merits of Christ and of His saints and so should be treated with all reverence, they have in fact nonetheless become a shocking exercise of greed. For who actually seeks the salvation of souls through indulgences, and not instead money for his coffers? ... The people are always left in ignorance, so that they come to think that by
gaining indulgences they are at once saved. 
 |author    = [[Martin Luther]]
 |source    = ''[[Ninety-five Theses]]''{{sfn|Wicks|1967|p=493}}
 |align     = center
 |width     = 66.6%
 |bgcolor   = #F5FAFF
 |title_bg  = #CEE0F2
 |qalign    = left
 |salign    = right
 }}

==Architecture==

[[File:Bellapais Hof ohne Baum.jpg|thumb|right|alt=Ruined walls and arches in a courtyard with cypres|Ruins of the walled courtyard of the Catholic [[Bellapais Abbey]] in Cyprus]]

The destruction of Christian shrines by the Turkomans featured prominently in Pope Urban's speech at Clermont. After capturing [[Bethlehem]], Jerusalem, and [[Nazareth]]—three of Christendom's holiest sites—the Franks launched ambitious construction programmes.{{sfn|Folda|2002|pp=138–139}} The archaeologist [[Denys Pringle]] observes that a "coherent and distinctive" architectural style emerged, shaped by the abundance of stone, scarcity of timber, and preference for flat-roofed designs.{{sfn|Pringle|2002|pp=155–156}} The medievalist Steve Tibble terms it the "architecture of fear", characterised by the absence of staircases in favour of movable ladders, the use of heavy timber bolts, and windows secured with iron bars.{{sfn|Tibble|2025|p=55}}

The most remarkable project was the rebuilding of the Church of the Holy Sepulchre, redesigned in the style of Western pilgrimage churches to enclose the [[Tomb of Jesus|Aedicule]], [[Calvary]], and Christ's Prison within one complex.{{sfn|Folda|2002|pp=142–143}} The fusion of local and Western architectural traditions is well illustrated by the Armenian [[Cathedral of Saint James, Jerusalem|Cathedral of Saint James]].{{sfn|Pringle|2002|p=158}} Coastal towns had multi-storey houses in Western Mediterranean style, with shops or loggias below and residences above. Frankish settlers often lived in newly founded villages laid out in rectangular plans.{{sfn|Pringle|2002|p=164}}

Western architectural development is especially visible in Cyprus. The Saint Sophia Cathedral in [[Nicosia]] (now [[Selimiye Mosque, Nicosia|Selimiye Mosque]]) was built in [[Early Gothic architecture|early Gothic]], though with terraced roofs. The [[Palazzo del Provveditore|Venetian governors' palace]] in Famagusta features a [[Renaissance architecture|Renaissance]] façade. Urban eastern Christian churches also adopted Western styles.{{sfn|Pringle|2002|pp=171–172}} In Frankish Greece, monastic orders and nobles erected Gothic monasteries and rebuilt existing buildings in Gothic style,{{refn|group=note|In Athens, the [[De la Roche family|De la Roche]] dukes converted the [[Propylaia (Acropolis of Athens)|Propylaia]] into a fortified palace embellishing it with Gothic elements.{{sfn|Bouras|2001|p=251}}}}{{sfn|Bouras|2001|pp=247–251}} In the Baltic, public buildings reflected Western styles, characterized by simplicity and precision.{{sfn|Christiansen|1997|p=220}}

==Arts==

{{Main|Crusader art}}

[[File:Egerton ms 1139!1 fse005r.jpg|thumb|right|alt=A richly decorated ivory plate depicting scenes from the life of King David|Ivory front cover of the [[Melisende Psalter]], {{circa|1135}}]]

In the three northern Crusader states, [[figurative art]] survives almost solely on coinage,{{refn|group=note|The art historian [[Jaroslav Folda]] identifies a large-format Bible, now in [[San Daniele del Friuli]], as a likely exception because of its distinctive style, blending Armenian, Byzantine, and Syriac elements—well suited to an Antiochene context.{{sfn|Folda|2002|p=148}}}} whereas Jerusalem left a much richer artistic legacy.{{sfn|Folda|2002|p=139}} These artefacts reveal significant [[Byzantine art|Byzantine influence]],{{sfn|Dodwell|1993|p=241}} although the earliest surviving decorations exhibit Western stylistic features.{{refn|group=note|Folda suggests that a life-sized silver sculpture of Christ was the first artefact placed in the Aedicule during the Crusader period, known only from a remark by [[Daniel the Traveller]], a pilgrim from Rus'.{{sfn|Folda|2002|p=140}}}}{{sfn|Folda|2002|p=140}} By the mid-12th{{nbsp}}century, both the Holy Sepulchre and the [[Church of the Nativity]] were decorated with mosaics.{{sfn|Dodwell|1993|p=241}}{{sfn|Folda|2002|pp=143–145}} Western artists working on illuminated manuscripts in Jerusalem also embraced Byzantine aesthetics.{{sfn|Dodwell|1993|pp=241, 243}} The finest example is the [[Melisende Psalter]], commissioned by [[Fulk, King of Jerusalem|King Fulk]] for [[Melisende, Queen of Jerusalem|Queen Melisende]] {{circa|1135}}.{{sfn|Dodwell|1993|p=242}}{{sfn|Folda|2002|p=141}} Jotischky describes Frankish sponsorship of [[icon]]s as perhaps the clearest sign of "Byzantine tastes in crusader arts", with surviving works primarily housed in [[Saint Catherine's Monastery]] on [[Mount Sinai]] and in Cyprus.{{sfn|Jotischky|2017|p=160}}

From Frankish Greece, little remains. A cycle of frescoes portraying [[Francis of Assisi]] survives in Istanbul's [[Kalenderhane Mosque]],{{sfn|Folda|2002|pp=148–149}} and a wall painting of Saints [[Anthony the Great|Anthony]] and [[James the Great|James]] in a gatehouse at [[Acronauplia]].{{sfn|Gerstel|2001|pp=264–266}} In the Baltic, the [[Clerical celibacy in the Catholic Church|celibate]] or [[endogamous]] elites rejected local traditions, preserving a distinctly Catholic and German culture.{{sfn|Christiansen|1997|p=218}}

==Literature==

Coinciding with the "[[Twelfth-Century Renaissance]]", the movement inspired a remarkable range of literary works,{{sfn|Routledge|2002|p=91}} including what historian Elizabeth Lapina describes as "an unusually large and varied body" of narrative sources.{{sfn|Lapina|2019|p=11}}

===Chronicles===

{{Main|List of sources for the Crusades}}

Early accounts of the First Crusade revived the tradition of comprehensive military history last seen in antiquity.{{sfn|Lapina|2019|p=19}} The ''[[Gesta Francorum|Deeds of the Franks]]'', completed by 1104, became the basis for later accounts by Raymond of Aguilers, [[Fulcher of Chartres]], and [[Robert of Rheims]]. These pro-papal writers portrayed Pope Urban as the key instigator, although the German chronicler [[Albert of Aachen]] credited Peter the Hermit.{{sfn|Tyerman|2011|pp=8–11, 15}}{{sfn|Jaspert|2006|p=38}}

Although the First Crusade remained the most extensively recorded, subsequent expeditions inspired new works by [[Odo of Deuil]], [[Otto of Freising]], and [[Oliver of Paderborn]].{{sfn|Lapina|2019|p=12}}{{sfn|Jotischky|2017|pp=94, 233}} Whereas early narratives were in Latin, three chroniclers of the Fourth Crusade—[[Geoffrey of Villehardouin]], [[Robert of Clari]], and [[Henri de Valenciennes]]—wrote in [[Old French]].{{sfn|Lapina|2019|p=14}} Many chroniclers focused on individual crusaders.{{refn|group=note|For instance, Geoffrey of Bouillon was Albert of Aachen's hero, [[Ralph of Caen]] dedicated his ''[[Gesta Tancredi|Deeds of Tancred]]'' to the Italo–Norman noble [[Tancred, Prince of Galilee|Tancred]],{{sfn|Constable|2001|p=4}} and [[Jean de Joinville]] wrote a [[hagiography]] about Louis{{nbsp}}IX.{{sfn|Lapina|2019|p=13}}}}{{sfn|Constable|2001|p=4}} Several authors blended [[prose]] and [[Verse (poetry)|verse]] in the hybrid {{transliteration|la|[[prosimetra]]}} form.{{sfn|Lapina|2019|p=14}}

A distinct literary genre emerged around the Crusader states. [[William of Tyre]]'s chronicle sought to rally Western support and sustain Frankish morale.{{sfn|Lapina|2019|pp=12, 20}} The ''[[Chronicle of the Morea]]'', central to Frankish Greece's history, survives in French, Greek, Aragonese, and Italian.{{sfn|Lock|1995|pp=21–22}} In the Baltic, the chronicler [[Henry of Livonia]] sympathized with Christianized natives, whereas the ''Livonian Rhymed Chronicle'' glorified Crusader brutality.{{sfn|Christiansen|1997|pp=94–96}}

===Songs===

{{Main|Crusade song}}

{{Quote box
 |title     = Excerpt from the Prologue to the ''[[Chanson d'Antioche|Song of Antioch]]''
 |quote     = Christians should take the sign of the Cross for His sake and seek revenge on the descendants of Antichrist. Our Lord asks you to go to Jerusalem to kill and confound the wicked pagans who refuse to believe in God and adore His works or pay heed to His commandments.
 |author    = Anonymous
 |source    = ''[[Chanson d'Antioche|Song of Antioch]]''{{sfn|Ailes|2019|p=34}}
 |align     = center
 |width     = 66.6%
 |bgcolor   = #F5FAFF
 |title_bg  = #CEE0F2
 |qalign    = left
 |salign    = right
 }}

[[File:Page of Lay of the Cid.jpg|thumb|right|alt=A page from an old codex|A page from a 14th-century manuscript of the ''[[Cantar de mio Cid|Song of My Cid]]'']]
[[File:Page of Lay of the Cid.ogg|thumb|right|Text of the page from the ''[[Cantar de mio Cid|Song of My Cid]]'']]

Robert of Rheims's chronicle inspired verses in the ''[[Chanson d'Antioche|Song of Antioch]]'', a French [[chanson de geste|epic poem]] recounting Antioch's siege.{{sfn|Tyerman|2011|pp=12–13}} This work launched a semi-historical [[Crusade cycle|cycle of Crusade epics]].{{sfn|Ailes|2019|pp=32–33}} Only 179{{nbsp}}vernacular songs survive, mostly in [[Occitan language|Occitan]] by troubadours, using traditional forms like {{transliteration|pro|[[sirventes]]}}, {{transliteration|pro|[[pastorella]]s}}, and {{transliteration|pro|[[planh]]s}}.{{sfn|Routledge|2002|pp=92–93}} The literary scholar Linda Paterson highlights the Occitan [[Marcabru]]'s praise of the Iberian crusades as especially powerful.{{sfn|Paterson|2019|pp=12, 14, 20}} Most French and Occitan songs date to the Third Crusade.{{sfn|Paterson|2019|p=41}} In Iberia, the ''[[Cantar de mio Cid|Song of My Cid]]'' recounts the exploits of the Castilian noble [[Rodrigo Díaz de Vivar]].{{sfn|Jaspert|2006|p=117}}

===Muslim, eastern Christian and Jewish works===

Though medieval Muslim scholars never treated the Crusades as a distinct subject, Muslim poets like Ibn al-Khayyat warned of the threat of the "[[Islamic view of the Trinity|polytheists]]".{{sfn|Hillenbrand|2018|pp=9, 69–71}} Only two Muslim texts record daily contact with Franks: the aristocrat [[Usama ibn Munqidh]]'s memoir and [[Ibn Jubayr]]'s pilgrimage account. Some Arabic epics—such as the tale of the warrior woman [[Dhu al-Himma Shalish|Dhat al-Himma]]—also reference the crusades.{{sfn|Hillenbrand|2018|pp=259–266}}

After the First Crusade, Byzantine writers increasingly treated Western Europeans as a single group, using terms like {{transliteration|he|Latini}}. [[Niketas Choniates]] and other chroniclers acknowledged Latin military skill but portrayed them as barbarians.{{sfn|Kazhdan|2001|pp=86–89}} Clashes between German crusaders and Byzantines during the Second Crusade inspired two poems likening the crusaders to wild beasts.{{sfn|Jeffreys|Jeffreys|2001|pp=101–109}} The political marriage of the Byzantine princess [[Theodora Komnene, Duchess of Austria|Theodora]] to the Crusader [[Henry Jasomirgott]] also drew hostile poetry, with her mother [[Eirene the Sevastokratorissa|Eirene]] calling her son-in-law a "flesh-eating beast".{{sfn|Jeffreys|Jeffreys|2001|pp=115–116}} Later, Byzantine vernacular literature absorbed motifs—knights, love, and adventure—from chivalric romances.{{sfn|Gerstel|2001|p=274}}

The earliest Armenian reference to the Crusades—a 1098 [[Colophon (publishing)|colophon]] to a legal text—speaks of the arrival of "the western nation of heroes". Chroniclers such as [[Matthew of Edessa]] cast the Crusades in apocalyptic terms, associating Frankish rule with the fourth kingdom in [[Daniel 2|Daniel's prophecy]].{{sfn|Thomson|2001|pp=72–75}} In 1144, the prelate [[Nerses Shnorhali]] composed a ''Lament for the Fall of Edessa'', voicing hope for Islam's future downfall.{{sfn|MacEvitt|2008|p=177}} The Cilician noble [[Sempad the Constable|Smbat]]'s ''Chronicle'' shows familiarity with Western customs.{{sfn|Thomson|2001|p=80}} 

The Rhineland massacres sparked a literary response unprecedented in European Jewish history. The ''[[Mainz Anonymous]]'', one of the earliest Hebrew accounts, inspired subsequent chronicles, including [[Eliezer ben Nathan]]'s.{{sfn|Shachar|2019|pp=105–106}} [[Kinnot|Laments]] commemorating the pogroms entered the [[Ninth of Av]] liturgy {{circa|1200}}.{{sfn|Shachar|2019|pp=109–110}} Jewish pilgrims such as [[Benjamin of Tudela]] recorded their journey in travelogues,{{sfn|Backman|2022|pp=480–481}} and an unknown Jew from France who settled in the Holy Land in 1211 wrote a treatise urging others to reclaim it for Judaism.{{sfn|Shachar|2019|pp=112–113}}

==Legacy==

[[File:Horses of Basilica San Marco bright.jpg|thumb|right|alt=A group of bronze statues of four horses harnessed for chariot driving|[[Horses of Saint Mark]], brought to Venice among the spoils of the [[Sack of Constantinople]]]]

Scholars disagree on how the movement shaped interethnic relations. Although the campaigns caused suffering and deepened religious tensions, their violence was typical for the era. The Crusades' impact on intercultural exchange remains uncertain, as trade and other channels also transmitted ideas and technologies. The Sack of Constantinople severely damaged Catholic–Orthodox relations, hindering cooperation against the Ottomans.{{sfn|Jaspert|2006|pp=166–168}} Even so, the Crusades delayed Ottoman expansion, and a final Ottoman push into Central Europe was repelled by a crusading force.{{sfn|Nicholson|2004|p=92}}

The movement fostered the consolidation of western states by removing a substantial portion of their militant local elites and establishing precedents for concentrated taxation. Expanded commercial contact with the wider world encouraged [[urbanisation]] and the development of urban autonomy in western Europe. The sale of landed property weakened traditional structures founded on the personal ties between vassal and lord.{{sfn|Blaydes|Paik|2016|pp=552–553}}

Crusading extended Western Christendom's frontiers in Iberia and the Baltic, promoting Catholic settlement and liturgical unity.{{sfn|Bartlett|1994|pp=11–24}} Political expansion sometimes brought [[language change]] or even [[language death|extinction]], as seen in the near-total disappearance of Arabic documents in formerly Muslim territories in Iberia by 1290 and the loss of [[Old Prussian language|Old Prussian]] by 1680.{{sfn|Bartlett|1994|pp=203–204}} Crusading also gave rise to national heroes and symbols, such as Denmark's flag, the [[Flag of Denmark|Dannebrog]].{{sfn|Tyerman|2019|p=468}} Few existing institutions, mostly offshoots of former military orders, trace their origins to the crusading movement. The idea of Christian violence as an act of love persists in some interpretations, such as [[liberation theology]].{{sfn|Riley-Smith|2002b|pp=385–389}} 

==Modern perceptions==

Into the 20th{{nbsp}}century, France and Britain invoked the Crusades to justify [[Sykes–Picot Agreement|ambitions in the Middle East]].{{sfn|Nicholson|2004|p=97}} Today, they often symbolize a long-standing civilisational conflict.{{sfn|Tyerman|2019|p=462}} After [[September 11 attacks|9/11]], President [[George W. Bush]] controversially called the war on terror a crusade.{{sfn|Phillips|2002|p=4}} Muslim fundamentalists often label adversaries as "crusaders",{{sfn|El-Azhari|2021|pp=45–46}} and terms like "neo-Crusades" appear in popular discussions about Western or Russian military presence in the Middle East.{{sfn|Al'Zoby|2021|p=24}} [[Anti-Zionism|Anti-Zionists]] frequently draw parallels between the Crusader states and modern [[Israel]].{{sfn|Menache|2021|p=72}} 

Crusaders often donated relics to churches, and across Western Europe, statutes, frescoes, and [[stained glass]] commemorated the crusades.{{refn|group=note|For example, stained-glass windows in [[Basilica of Saint-Denis|Saint Denis Abbey]] depict scenes from the First Crusade.{{sfn|Tyerman|2019|pp=100, 102, 252}}}} During the [[Romantic period]], medieval crusading literature inspired artists, as seen in the 1830s decoration of [[Salles des Croisades|five Versailles]] rooms with 120{{nbsp}}paintings.{{sfn|Constable|2001|p=8}}{{sfn|Tyerman|2011|p=144}} Major works like ''[[La Gerusalemme liberata|Jerusalem Delivered]]'' by [[Torquato Tasso]] influenced later writers.{{sfn|Nicholson|2004|p=95}} [[Walter Scott]]'s ''[[Ivanhoe]]'' (1819) and ''[[The Talisman (Scott novel)|The Talisman]]'' (1825) shaped popular depictions despite historical inaccuracies.{{sfn|Tyerman|2019|p=454}} To this day, Crusades-themed [[epic film]]s exploit and reinterpret medieval imagery as both source and mirror of modern nations and conflicts.{{refn|group=note|Early examples include [[Cecil B. DeMille]]'s ''[[The Crusades (1935 film)|The Crusades]]'', promoting [[United States non-interventionism|US neutrality]] in global conflicts,{{sfn|Haydock|2009a|pp=1, 3}} and [[Sergei Eisenstein]]'s monumental ''[[Alexander Nevsky (film)|Alexander Nevsky]]'', portraying the Teutonic Knights as Nazi precursors.{{sfn|Haydock|2009b|p=51}} In Middle Eastern cinema, [[Youssef Chahine]]'s {{transliteration|ar|[[Al Nasser Salah Ad-Din (film)|Al Nasser Salah Ad-Din]]}} ('Saladin the Victorious') presents Saladin as a medieval counterpart to the Egyptian president [[Gamal Abdel Nasser]].{{sfn|Sturtevant|2009|p=142}}}}{{sfn|Haydock|2009a|p=1}} Depictions of the Crusades in modern cinema frequently draw historians' criticism; for instance, the argument of Riley-Smith that in ''[[Kingdom of Heaven (film)|Kingdom of Heaven]],'' the director [[Ridley Scott]] conveyed a historical perspective akin to [[Osama bin Laden]]'s.{{sfn|Haydock|2009a|p=16}}

==Historiography==

{{Main|Historiography of the Crusades}}
{{See also|Historians and histories of the Crusades}}

[[File:HistorieHolyWarreFuller1647.jpg|thumb|right|alt=An engraving depicting two churches connected with a road filled with armed and unarmed people|Title page of the third edition of ''The Historie of the Holy Warre,'' by [[Thomas Fuller]] (1647)]]

Western Crusade [[historiography]]'s first phase began with early First Crusade accounts and continued until {{circa|1600}}, amid ongoing Muslim–Christian conflict. Medieval Catholic historians interpreted the Crusades through an [[Irredentism|irredentist]] lens, framing them as efforts to reclaim Christian territory.{{refn|group=note|The 14th-century Castilian aristocrat [[Juan Manuel]] explicitly stated in his {{lang|es|Libro de los estados ('Book of the States')}} that there "will be war until the Christians have recovered the lands that the Muslims seized from them".{{sfn|Constable|2001|p=4}}}}{{sfn|Constable|2001|pp=2, 4}} A second phase began in 1611 with the publication of primary sources by [[Jacques Bongars]], later used by [[Thomas Fuller]], who completed a general Crusade history in 1639. Scholarship reflected strong ideological leanings: Protestant writers like Fuller were critical, whereas Catholic historians such as the Jesuit [[Louis Maimbourg]] were more sympathetic. Over time, terminology shifted—by the 18th{{nbsp}}century, neutral terms like {{transliteration|de|Kreuzzug}}, {{transliteration|fr|croisade}}, and crusade replaced earlier expressions like "holy war".{{sfn|Tyerman|2011|p=77}} [[Age of Enlightenment|Enlightenment]] thinkers grew increasingly critical, exemplified by [[Voltaire]]'s reference to the "madness of the crusades" (1751).{{sfn|Constable|2001|p=8}}{{sfn|Tyerman|2011|pp=78–79}}

The third phase, beginning {{circa|1800}}, was shaped by nationalism and Romanticism, prompting a more positive reassessment. Landmark works included [[Friedrich Wilken]]'s ''History of the Crusades from Eastern and Western Sources'' and [[Joseph-François Michaud]]'s ''History of the Crusades''. In the 1830s, [[Leopold von Ranke]] introduced modern [[source criticism]], later applied by [[Heinrich von Sybel]] to the First Crusade. International collaboration advanced with the 1875 founding of the {{lang|fr|[[Société de l'Orient Latin]]}} ("Society of the Latin East"). Critical editions of source material supported influential histories by [[René Grousset]] (1930s) and [[Steven Runciman]] (1950s). Major later surveys include the ''[[Wisconsin Collaborative History of the Crusades]]'' (1955–1989) and the ''[[Oxford Illustrated Histories|Oxford Illustrated History of the Crusades]]'' (1995).{{sfn|Constable|2001|pp=9–10}} Early-21st-century scholarly debates focus on defining the Crusades, assessing participants' motives, and interpreting the movement through colonial or integrative models,{{sfn|Jotischky|2017|pp=7–21}} and earlier [[Eurocentrism|Eurocentric]] narratives are increasingly being challenged.{{sfn|Lock|2006|p=272}}

Muslim historiography largely overlooked the topic until 1899, when the Egyptian [[Sayyid ʿAli al-Ḥarīrī]] wrote the first Arabic account.{{sfn|Nicholson|2004|p=97}}{{sfn|Asbridge|2012|p=674}} Today, the {{transliteration|ar|al-hurub al-salibyya}} ("wars of the cross") are central to education in Egypt and Jordan—although Jordan places less emphasis on religious aspects.{{sfn|El-Azhari|2021|p=45}}{{sfn|Al'Zoby|2021|p=24}} The Syrian historian Soheil Zakkar compiled a four-volume encyclopaedia framing the anti-Frankish campaigns as a struggle for Arab liberation.{{sfn|Isa|2021|p=62}} 

Greek historians have mainly studied the {{transliteration|he|stavrósforía}} ("bearing of the cross") within Byzantine history,{{sfn|Chrissis|2021|p=42}} but Greek Cypriot scholars emphasize that the Third Crusade severed Cyprus from Byzantium and introduced a repressive regime.{{sfn|Coureas|2021|pp=39–40}} In Israel, [[Joshua Prawer]]'s work established Crusade studies as a distinct academic field.{{sfn|Menache|2021|p=72}}

== See also ==
* [[History of Christianity]]
* [[Religious violence]]
* [[Christianity and violence]]

==Notes==
{{Reflist|group=note}}

== References ==
{{Reflist|20em}}

== Bibliography ==
{{refbegin|30em}}
*{{cite book|last=Ailes|first=Marianne|editor-last=Bale|editor-first=Anthony|editor-link=Anthony Bale|title=The Cambridge Companion to the Literature of the Crusades|url=https://www.cambridge.org/core/books/cambridge-companion-to-the-literature-of-the-crusades/26499BD90F47509267FE028A2B1786DF|series=Cambridge Companions to Literature|year=2019|chapter=The {{transliteration|fr|Chanson de geste}}|pages=25–38|publisher=[[Cambridge University Press]]|isbn=978-1-1084-7451-1}}
*{{cite book|last=Al'Zoby|first=Mazhar|editor1-last=Hinz|editor1-first=Felix|editor2-last=Meyer-Hamme|editor2-first=Johannes|title=Controversial Histories—Current Views on the Crusades|url=https://www.routledge.com/Controversial-Histories---Current-Views-on-the-Crusades-Engaging-the-Crusades-Volume-Three/Hinz-Meyer-Hamme/p/book/9780367511272?srsltid=AfmBOopOgujlA_ir6HRkH7RIR82ngtd6AnQAAc6FNZuW63ug7kVIzeDf|series=Engaging the Crusades|volume=Three|year=2021|chapter='Frankish Invasions' and 'A Cosmic Struggle between Islam and Christianity'—A View from Jordan|pages=24–25|publisher=[[Routledge]]|isbn=978-0-367-51127-2}}
*{{cite book|last=Asbridge|first=Thomas|author-link=Thomas Asbridge|year=2012|orig-year=2010|title=The Crusades: The War for the Holy Land|publisher=[[Simon and Schuster]]|url=https://www.simonandschuster.co.uk/books/The-Crusades/Thomas-Asbridge/9781471196430|isbn=978-1-8498-3688-3}}
*{{cite book|last=Backman|first=Clifford R.|year=2022|orig-year=2009|title=The Worlds of Medieval Europe|edition=Fourth|url=https://global.oup.com/academic/product/the-worlds-of-medieval-europe-9780197571538?q=The%20Worlds%20of%20Medieval%20Europe&lang=en&cc=us|publisher=[[Oxford University Press]]|isbn=978-0-1975-7153-8}}
*{{cite journal|last1=Blaydes|first1=Lisa|last2=Paik|first2=Christopher|title=The Impact of Holy Land Crusades on State Formation: War Mobilization, Trade Integration, and Political Development in Medieval Europe|journal=[[International Organization (journal)|International Organization]]|volume=70|issue=3|pages=551–586|date=Summer 2016|url=https://www.cambridge.org/core/journals/international-organization/article/abs/impact-of-holy-land-crusades-on-state-formation-war-mobilization-trade-integration-and-political-development-in-medieval-europe/99CD4B614F6EFEBD99EB58F365195A01|doi=10.1017/S0020818316000096|jstor=24758130|issn=0020-8183|url-access=subscription}} 
*{{cite book|last=Bartlett|first=Robert|author-link=Robert Bartlett (historian)|year=1994|orig-year=1993|title=The Making of Europe: Conquest, Colonization and Cultural Change, 950–1350|url=https://www.penguin.co.uk/books/14965/the-making-of-europe-by-robert-bartlett/9780140154092|publisher=[[Penguin Books]]|isbn=978-0-140-15409-2}}
*{{cite book|last=Bouras|first=Charalambos|author-link=Charalambos Bouras|year=2001|chapter=The Impact of Frankish Architecture on Thirteenth-Century Byzantine Architecture|editor1-last=Laiou|editor1-first=Angeliki E.|editor1-link=Angeliki Laiou|editor2-last=Mottahedeh|editor2-first=Roy Parviz|editor2-link=Roy Mottahedeh|title=The Crusades from the Perspectives of Byzantium and the Muslim World|pages=247–262|publisher=[[Dumbarton Oaks Research Library]]|url=https://www.doaks.org/resources/publications/books/the-crusades-from-the-perspective-of-byzantium-and|isbn=978-0-88402-277-0}}
*{{cite book|last=Brundage|first=James A.|author-link=James A. Brundage|year=1997|chapter=Crusaders and Jurists: The Legal Consequences of Crusader Status|editor-last=Vauchez|editor-first=André|title=Le concile de Clermont de 1095 et l'appel à la croisade. Actes du Colloque Universitaire International de Clermont-Ferrand (23-25 juin 1995)|pages=141–154|series=Publications de l'École française de Rome|volume=236|publisher=[[École française de Rome]]|url=https://www.persee.fr/doc/efr_0223-5099_1997_act_236_1_6053|isbn=978-2-7283-0388-5}}
*{{cite book|last=Bull|first=Marcus|author-link=Marcus Bull|year=2002|orig-year=1999|chapter=Origins|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=15–34|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=Bysted|first=Ane L.|year=2014|title=The Crusade Indulgence: Spiritual Rewards and the Theology of the Crusades, {{circa}} 1095–1216|series=History of Warfare|volume=103|publisher=[[BRILL]]|url=https://brill.com/display/title/13076|isbn=978-9-0042-8043-4}}
*{{cite book|last=Carr|first=Mike|year=2016|orig-year=2014|title=Merchant Crusaders in the Aegean, 1291–1352|series=Warfare in History|url=https://boydellandbrewer.com/9781783274055/merchant-crusaders-in-the-aegean-1291-1352/|publisher=[[The Boydell Press]]|isbn=978-1-7832-7405-5}}
*{{cite book|last=Caspi-Reisfeld|first=Keren|editor1-last=Edgington|editor1-first=Susan B.|editor2-last=Lambert|editor2-first=Sarah|title=Gendering the Crusades|year=2001|chapter=Women Warriors during the Crusades, 1095–1254|pages=94–107|publisher=[[University of Wales Press]]|isbn=978-0-7083-1698-6}}
*{{cite book|last=Cassidy-Welch|first=Megan|author-link=Megan Cassidy-Welch|year=2023|title=Crusades and Violence|publisher=ARC Humanities Press|url=https://www.arc-humanities.org/9781641894753/crusades-and-violence/|isbn=978-1-6418-9475-3}}
*{{cite book|last=Chazan|first=Robert|author-link=Robert Chazan|year=2006|title=The Jews of Medieval Western Christendom, 1000–1500|series=Cambridge Medieval Textbooks|url=https://www.cambridge.org/core/books/jews-of-medieval-western-christendom/383F64F06E6E19CA875FA38AA575A8CB|publisher=[[Cambridge University Press]]|isbn=978-0-521-84666-0}}
*{{cite book|last=Chrissis|first=Nikolaos G.|editor1-last=Hinz|editor1-first=Felix|editor2-last=Meyer-Hamme|editor2-first=Johannes|title=Controversial Histories—Current Views on the Crusades|url=https://www.routledge.com/Controversial-Histories---Current-Views-on-the-Crusades-Engaging-the-Crusades-Volume-Three/Hinz-Meyer-Hamme/p/book/9780367511272?srsltid=AfmBOopOgujlA_ir6HRkH7RIR82ngtd6AnQAAc6FNZuW63ug7kVIzeDf|series=Engaging the Crusades|volume=Three|year=2021|chapter=Western Agression and Greco—Latin Interaction—A View from Syria|pages=42–44|publisher=[[Routledge]]|isbn=978-0-367-51127-2}}
*{{cite book|last=Christiansen|first=Eric|author-link=Eric Christiansen|orig-year=1980|year=1997|title=The Northern Crusades|edition=Second|publisher=[[Penguin Books]]|url=https://www.penguin.co.uk/books/23687/the-northern-crusades-by-eric-christiansen/9780140266535|isbn=978-0-14-026653-5}}
*{{cite book|last=Cobb|first=Paul M.|author-link=Paul M. Cobb|year=2016|orig-year=2014|title=The Race for Paradise: An Islamic History of the Crusades|url=https://global.oup.com/academic/product/the-race-for-paradise-9780190614461?cc=us&lang=en&|publisher=[[Oxford University Press]]|isbn=978-0-1987-8799-0}}
*{{cite book|last=Constable|first=Giles|author-link=Giles Constable|year=2001|chapter=The Historiography of the Crusades|editor1-last=Laiou|editor1-first=Angeliki E.|editor1-link=Angeliki Laiou|editor2-last=Mottahedeh|editor2-first=Roy Parviz|editor2-link=Roy Mottahedeh|title=The Crusades from the Perspectives of Byzantium and the Muslim World|pages=1–22|publisher=[[Dumbarton Oaks Research Library]]|url=https://www.doaks.org/resources/publications/books/the-crusades-from-the-perspective-of-byzantium-and|isbn=978-0-88402-277-0}}
*{{cite book|last=Coureas|first=Nicholas|editor1-last=Hinz|editor1-first=Felix|editor2-last=Meyer-Hamme|editor2-first=Johannes|title=Controversial Histories—Current Views on the Crusades|url=https://www.routledge.com/Controversial-Histories---Current-Views-on-the-Crusades-Engaging-the-Crusades-Volume-Three/Hinz-Meyer-Hamme/p/book/9780367511272?srsltid=AfmBOopOgujlA_ir6HRkH7RIR82ngtd6AnQAAc6FNZuW63ug7kVIzeDf|series=Engaging the Crusades|volume=Three|year=2021|chapter=The Crusades Confront the Orthdoxs—A Greek Cypriot Viewpoint|pages=39–41|publisher=[[Routledge]]|isbn=978-0-367-51127-2}}
*{{cite book|last=Dennis|first=George T.|year=2001|chapter=Defenders of the Christian People: Holy War in Byzantium|editor1-last=Laiou|editor1-first=Angeliki E.|editor1-link=Angeliki Laiou|editor2-last=Mottahedeh|editor2-first=Roy Parviz|editor2-link=Roy Mottahedeh|title=The Crusades from the Perspectives of Byzantium and the Muslim World|pages=31–40|publisher=[[Dumbarton Oaks Research Library]]|url=https://www.doaks.org/resources/publications/books/the-crusades-from-the-perspective-of-byzantium-and|isbn=978-0-88402-277-0}}
*{{cite book|last=Dickson|first=Gary|editor-last=Murray|editor-first=Alan V.|title=K–Q|year=2006|chapter=Popular Crusades|pages=975–979|series=The Crusades: An Encyclopedia|volume=III|publisher=[[ABC Clio]]|isbn=978-1-57607-862-4}}
*{{cite book|last=Dodwell|first=C. R.|author-link=Charles Reginald Dodwell|year=1993|title=The Pictorial Arts of the West: 800–1200|series=Pelican History of Art|url=https://archive.org/details/pictorialartsofw00dodw|publisher=[[Yale University Press]]|isbn=978-0-300-06493-3}}
*{{cite book|last=Edbury|first=Peter|year=2002|orig-year=1999|chapter=The Latin East, 1291–1661|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=291–322|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=El-Azhari|first=Taef Kamal|editor1-last=Hinz|editor1-first=Felix|editor2-last=Meyer-Hamme|editor2-first=Johannes|title=Controversial Histories—Current Views on the Crusades|url=https://www.routledge.com/Controversial-Histories---Current-Views-on-the-Crusades-Engaging-the-Crusades-Volume-Three/Hinz-Meyer-Hamme/p/book/9780367511272?srsltid=AfmBOopOgujlA_ir6HRkH7RIR82ngtd6AnQAAc6FNZuW63ug7kVIzeDf|series=Engaging the Crusades|volume=Three|year=2021|chapter=The Former Victors over the Crusades in Palestine—A View from Egypt|pages=45–46|publisher=[[Routledge]]|isbn=978-0-367-51127-2}}
*{{cite book|last=Ellenblum|first=Ronnie|author-link=Ronnie Ellenblum|year=2012|title=The Collapse of the Eastern Mediterranean: Climate Change and the Decline of the East, 950–1072|url=https://www.cambridge.org/core/books/collapse-of-the-eastern-mediterranean/92C6970E1D450DC41EA44B9DD1B53696|publisher=[[Cambridge University Press]]|isbn=978-1-1070-2335-2}}
*{{cite book|last=Folda|first=Jaroslav|author-link=Jaroslav Folda|year=2002|orig-year=1999|chapter=Art in the Latin East, 1098–1291|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=138–154|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=Forey|first=Alan|author-link=Alan Forey|year=2002|orig-year=1999|chapter=The Military Orders, 1120–1312|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=15–34|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=France|first=John|year=1999|title=Western Warfare in the Age of the Crusades, 1000–1300|url=https://www.cornellpress.cornell.edu/book/9780801486074/western-warfare-in-the-age-of-the-crusades-10001300/|publisher=[[Cornell University Press]]|isbn=978-0-8014-3671-0}}
*{{cite book|last=Friedman|first=Yvonne|editor1-last=Edgington|editor1-first=Susan B.|editor2-last=Lambert|editor2-first=Sarah|title=Gendering the Crusades|year=2001|chapter=Captivity and Randsom: The Experience of Women|pages=121–139|publisher=[[University of Wales Press]]|isbn=978-0-7083-1698-6}}
*{{cite book|last=Gerstel|first=Sharon E. J.|author-link=Sharon E. J. Gerstel|year=2001|chapter=Art and Identity in the Medieval Morea|editor1-last=Laiou|editor1-first=Angeliki E.|editor1-link=Angeliki Laiou|editor2-last=Mottahedeh|editor2-first=Roy Parviz|editor2-link=Roy Mottahedeh|title=The Crusades from the Perspectives of Byzantium and the Muslim World|pages=263–286|publisher=[[Dumbarton Oaks Research Library]]|url=https://www.doaks.org/resources/publications/books/the-crusades-from-the-perspective-of-byzantium-and|isbn=978-0-88402-277-0}}
*{{cite book|last=Ghazarian|first=Jacob G.|orig-year=2000|year=2005|title=The Armenian Kingdom in Cilicia during the Crusades: The Integration of Cilician Armenians with the Latins, 1080–1393|url=https://www.routledge.com/The-Armenian-Kingdom-in-Cilicia-During-the-Crusades-The-Integration-of-Cilician-Armenians-with-the-Latins-1080-1393/Ghazarian/p/book/9781138862579?srsltid=AfmBOooRaU1pAzvYggcZUqJhZehnNnwN08PdvUmMO6MSb1gWoGYkUqf7|publisher=[[RoutledgeCurzon]]|isbn=978-0-7007-1418-6}}
*{{cite book|last=Haydock|first=Nickolas|editor1-last=Haydock|editor1-first=Nickolas|editor2-last=Risden|editor2-first=E. L.|title=Hollywood in the Holy Land: Essays on Film Depictions of the Crusades and Christian–Muslim Clashes|url=https://mcfarlandbooks.com/product/hollywood-in-the-holy-land/?srsltid=AfmBOopuiVahfQL__zOad3yo8W90X5MFpXKLekuv_eonEFN8t62-KLD4|year=2009a|chapter='The Unseen Cross Upon the Breast': Medievalism, Orientalism, and Discontent|pages=1–38|publisher=[[McFarland & Company]]|isbn=978-0-7864-4156-3}}
*{{cite book|last=Haydock|first=Nickolas|editor1-last=Haydock|editor1-first=Nickolas|editor2-last=Risden|editor2-first=E. L.|title=Hollywood in the Holy Land: Essays on Film Depictions of the Crusades and Christian–Muslim Clashes|url=https://mcfarlandbooks.com/product/hollywood-in-the-holy-land/?srsltid=AfmBOopuiVahfQL__zOad3yo8W90X5MFpXKLekuv_eonEFN8t62-KLD4|year=2009b|chapter=Homeland Security: Northern Crusades through the East–European Eyes of Alexander Nevsky and the Nevsky Tradition|pages=47–96|publisher=[[McFarland & Company]]|isbn=978-0-7864-4156-3}}
*{{cite book|last=Hillenbrand|first=Carole|author-link=Carole Hillenbrand|orig-year=1999|year=2018|title=The Crusades: Islamic Perspectives|url=https://edinburghuniversitypress.com/book-the-crusades.html|publisher=[[Edinburgh University Press]]|isbn=978-0-7486-0630-6}}
*{{cite book|last=Hodgson|first=Natasha R.|orig-year=2007|year=2017|title=Women, Crusading an the Holy Land in Historical Narrative|series=Warfare in History|url=https://boydellandbrewer.com/9781783272709/women-crusading-and-the-holy-land-in-historical-narrative/|publisher=[[The Boydell Press]]|isbn=978-1-78327-270-9}}
*{{cite book|last=Hornby|first=A. S.|author-link=A. S. Hornby|editor1-last=Wehmeier|editor1-first=Sally|editor2-last=McIntosh|editor2-first=Colin|editor3-last=Turnbull|editor3-first=Joanna|editor4-last=Ashby|editor4-first=Michael|orig-year=1948|year=2005|title=[[Oxford Advanced Learner's Dictionary]]|edition=Seventh|publisher=[[Oxford University Press]]|isbn=978-0-1943-1606-4}}
*{{cite book|last=Housley|first=Norman|author-link=Norman Housley|year=2002|orig-year=1999|chapter=The Crusading Movement, 1274–1700|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=258–290|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=Irwin|first=Robert|year=2002|orig-year=1999|chapter=Islam and the Crusades, 1096–1699|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=211–257|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=Isa|first=Mohamad|editor1-last=Hinz|editor1-first=Felix|editor2-last=Meyer-Hamme|editor2-first=Johannes|title=Controversial Histories—Current Views on the Crusades|url=https://www.routledge.com/Controversial-Histories---Current-Views-on-the-Crusades-Engaging-the-Crusades-Volume-Three/Hinz-Meyer-Hamme/p/book/9780367511272?srsltid=AfmBOopOgujlA_ir6HRkH7RIR82ngtd6AnQAAc6FNZuW63ug7kVIzeDf|series=Engaging the Crusades|volume=Three|year=2021|chapter=A Sate of Continuous Rape and Violation—A View from Syria|pages=62–63|publisher=[[Routledge]]|isbn=978-0-367-51127-2}}
*{{cite book|last=Jaspert|first=Nikolas|year=2006|orig-year=2003|title=The Crusades|publisher=[[Routledge]]|url=https://www.routledge.com/The-Crusades/Jaspert/p/book/9780415359689|isbn=978-0-4153-5968-9}}
*{{cite book|last1=Jeffreys|first1=Elizabeth|author1-link=Elizabeth Jeffreys|last2=Jeffreys|first2=Michael|year=2001|chapter=The "Wild Beast from the West": Immediate Literary Reactions in Byzantium to the Second Crusade|editor1-last=Laiou|editor1-first=Angeliki E.|editor1-link=Angeliki Laiou|editor2-last=Mottahedeh|editor2-first=Roy Parviz|editor2-link=Roy Mottahedeh|title=The Crusades from the Perspectives of Byzantium and the Muslim World|pages=101–116|publisher=[[Dumbarton Oaks Research Library]]|url=https://www.doaks.org/resources/publications/books/the-crusades-from-the-perspective-of-byzantium-and|isbn=978-0-88402-277-0}}
*{{cite book|last=Jotischky|first=Andrew|year=2017|orig-year=2004|title=Crusading and the Crusader States|edition=Second|publisher=[[Routledge]]|url=https://www.routledge.com/Crusading-and-the-Crusader-States/Jotischky-Jotischky/p/book/9781138808065|isbn=978-1-1388-0806-5}}
*{{cite book|last=Kazhdan|first=Alexander|author-link=Alexander Kazhdan|year=2001|chapter=Latins and Franks in Byzantium: Perception and Reality from the Eleventh to the Twelfth Century|editor1-last=Laiou|editor1-first=Angeliki E.|editor1-link=Angeliki Laiou|editor2-last=Mottahedeh|editor2-first=Roy Parviz|editor2-link=Roy Mottahedeh|title=The Crusades from the Perspectives of Byzantium and the Muslim World|pages=83–100|publisher=[[Dumbarton Oaks Research Library]]|url=https://www.doaks.org/resources/publications/books/the-crusades-from-the-perspective-of-byzantium-and|isbn=978-0-88402-277-0}}
*{{cite book|last=Kostick|first=Conor|author-link=Conor Kostick|year=2008|title=The Social Structure of the First Crusade|series=The Medieval Mediterranean: Peoples, Economies and Cultures, 400–1500|volume=76|publisher=[[Brill Publishers|Brill]]|url=https://brill.com/display/title/13734|isbn=978-90-04-16665-3}}
*{{cite book|last=Lapina|first=Elizabeth|editor-last=Bale|editor-first=Anthony|editor-link=Anthony Bale|title=The Cambridge Companion to the Literature of the Crusades|url=https://www.cambridge.org/core/books/cambridge-companion-to-the-literature-of-the-crusades/26499BD90F47509267FE028A2B1786DF|series=Cambridge Companions to Literature|year=2019|chapter=Crusader Chronicles|pages=11–24|publisher=[[Cambridge University Press]]|isbn=978-1-1084-7451-1}}
*{{cite journal|last=Latham|first=Andrew|title=Theorizing the Crusades: Identity, Institutions, and Religious War in Medieval Latin Christendom|journal=[[International Studies Quarterly]]|volume=5|issue=1|pages=223–243|date=March 2011|url=https://academic.oup.com/isq/article/55/1/223/1789102|doi=10.1111/j.1468-2478.2010.00642.x|jstor=23019520|issn=0020-8833}}
*{{cite book|last=Lilie|first=Ralph-Johannes|author-link=Ralph-Johannes Lilie|year=1993|orig-year=1981|title=Byzantium and the Crusader States, 1096-1204|url=https://global.oup.com/academic/product/byzantium-and-the-crusader-states-1096-1204-9780198204077?cc=us&lang=en&|publisher=[[Oxford University Press]]|isbn=978-0-19-820407-7}}
*{{cite book|last=Lloyd|first=Simon|year=2002|orig-year=1999|chapter=The Crusading Movement, 1096–1274|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=35–67|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=Lock|first=Peter|year=1995|title=The Franks in the Aegean, 1204–1500|publisher=[[Longman]]|url=https://archive.org/details/franksinaegean120000lock|isbn=978-0-58-205139-3}}
*{{cite book|last=Lock|first=Peter|year=2006|title=The Routledge Companion to the Crusades|series=Routledge Companion to History|publisher=[[Routledge]]|url=https://www.routledge.com/The-Routledge-Companion-to-the-Crusades/Lock/p/book/9780415393126|isbn=978-0-4153-9312-6}}
*{{cite book|last=Luttrell|first=Anthony|author-link=Anthony Luttrell|year=2002|orig-year=1999|chapter=The Military Orders, 1312–1798|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=323–362|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=MacEvitt|first=Christopher|year=2008|title=The Crusades and the Christian World of the East: Rough Tolerance|series=The Middle Ages|publisher=[[University of Pennsylvania Press]]|url=https://www.penguin.com.au/books/gods-war-9780141904313|isbn=978-0-8122-2083-4}}
*{{cite book|last=Madden|first=Thomas F.|year=2013|title=The Concise History of the Crusades|edition=Third|series=Critical Issues in World and International History|publisher=[[Rowman & Littlefield]]|url=https://rowman.com/ISBN/9781442215757/The-Concise-History-of-the-Crusades-Third-Student-Edition|isbn=978-1-4422-1575-7}}
*{{cite book|last=Mallett|first=Alex|year=2020|orig-year=2014|title=Popular Muslim Reactions to the Franks in the Levant, 1097–1291|publisher=[[Routledge]]|url=https://www.routledge.com/Popular-Muslim-Reactions-to-the-Franks-in-the-Levant-1097-1291/Mallett/p/book/9780367601034?srsltid=AfmBOoq7OPowK_JYU2qypMrYuuamyVBhYW513M2i0SyMF5pWNZn-NeAm|isbn=978-0-367-60103-4}}
*{{cite book|last=Mayer|first=Hans Eberhard|author-link=Hans Eberhard Mayer|year=2009|orig-year=1965|title=The Crusades|edition=Second|translator=John Gillingham|translator-link=John Gillingham|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-crusades-9780198730972?cc=hu&lang=en&|isbn=978-0-19-873097-2}}
*{{cite book|last=Menache|first=Sophia|editor1-last=Hinz|editor1-first=Felix|editor2-last=Meyer-Hamme|editor2-first=Johannes|title=Controversial Histories—Current Views on the Crusades|url=https://www.routledge.com/Controversial-Histories---Current-Views-on-the-Crusades-Engaging-the-Crusades-Volume-Three/Hinz-Meyer-Hamme/p/book/9780367511272?srsltid=AfmBOopOgujlA_ir6HRkH7RIR82ngtd6AnQAAc6FNZuW63ug7kVIzeDf|series=Engaging the Crusades|volume=Three|year=2021|chapter=In the Frontier of the Former Kingdom of Jerusalem: Risk of Misunderstanding—A View from Israel|pages=72–74|publisher=[[Routledge]]|isbn=978-0-367-51127-2}}
*{{cite book|last=Morris|first=Colin|year=2001|orig-year=1989|title=The Papal Monarchy: The Western Church from 1050 to 1250|series=Oxford History of the Christian Church|url=https://global.oup.com/academic/product/the-papal-monarchy-9780198269250?cc=hu&lang=en&|publisher=[[Clarendon Press]]|isbn=978-0-19-826925-0}}
*{{cite book|last=Murray|first=Alan V.|author-link=Alan V. Murray|editor-last=Murray|editor-first=Alan V.|title=A–C|year=2006|chapter=Preface|pages=xxxi–xxxii|series=The Crusades: An Encyclopedia|volume=I|publisher=[[ABC Clio]]|isbn=978-1-57607-862-4}}
*{{cite book|last=Nicholson|first=Helen|author-link=Helen J. Nicholson|year=2004|title=The Crusades|series=Greenwood Guides to Historic Events of the Medieval World|publisher=[[Greenwood Press]]|url=https://www.bloomsbury.com/us/crusades-9780313326851/|isbn=978-0-313-32685-1}}
*{{cite book|last=O'Callaghan|first=Joseph F.|year=2003|title=Reconquest and Crusade in Medieval Spain|series=The Middle Ages|publisher=[[University of Pennsylvania Press]]|url=https://www.pennpress.org/9780812218893/reconquest-and-crusade-in-medieval-spain/|isbn=978-0-8122-1889-3}}
*{{cite book|last=Paterson|first=Linda|editor-last=Bale|editor-first=Anthony|editor-link=Anthony Bale|title=The Cambridge Companion to the Literature of the Crusades|url=https://www.cambridge.org/core/books/cambridge-companion-to-the-literature-of-the-crusades/26499BD90F47509267FE028A2B1786DF|series=Cambridge Companions to Literature|year=2019|chapter=The Troubadours and Their Lyrics|pages=39–53|publisher=[[Cambridge University Press]]|isbn=978-1-1084-7451-1}}
*{{cite book|last=Phillips|first=Jonathan|year=2002|orig-year=1999|chapter=The Latin East, 1098–1291|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=111–137|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=Phillips|first=Jonathan|orig-year=2002|year=2014|title=The Crusades, 1095–1204|edition=Second|series=Seminar Studies|publisher=[[Routledge]]|url=https://www.routledge.com/The-Crusades-1095-1204/Phillips/p/book/9781405872935?srsltid=AfmBOorfKKPGt_Glgv5UrlxEUpeqp54bXB6UtNe4mpf5-dMj29XmQEZb|isbn=978-1-4058-7293-5}}
*{{cite book|last=Polejowski|first=Karol|editor1-last=Hinz|editor1-first=Felix|editor2-last=Meyer-Hamme|editor2-first=Johannes|title=Controversial Histories—Current Views on the Crusades|url=https://www.routledge.com/Controversial-Histories---Current-Views-on-the-Crusades-Engaging-the-Crusades-Volume-Three/Hinz-Meyer-Hamme/p/book/9780367511272?srsltid=AfmBOopOgujlA_ir6HRkH7RIR82ngtd6AnQAAc6FNZuW63ug7kVIzeDf|series=Engaging the Crusades|volume=Three|year=2021|chapter=From Grunwald to Vienna—A View from Poland|pages=81–83|publisher=[[Routledge]]|isbn=978-0-367-51127-2}}
*{{cite book|last=Pringle|first=Denys|author-link=Denys Pringle|year=2002|orig-year=1999|chapter=Architecture in the Latin East, 1098–1571|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=155–175|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=Riley-Smith|first=Jonathan|author-link=Jonathan Riley-Smith|year=2002a|orig-year=1999|chapter=The State of Mind of Crusaders to the East, 1095–1300|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=68–89|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=Riley-Smith|first=Jonathan|year=2002b|orig-year=1999|chapter=Revival and Survival|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=385–389|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=Riley-Smith|first=Jonathan|year=2005|orig-year=2001|chapter=The Crusading Movement|pages=127–140|editor1-last=Hartmann|editor1-first=Anja V.|editor2-last=Hauser|editor2-first=Beatrice|title=War, Peace and World Orders in European History|url=https://www.routledge.com/War-Peace-and-World-Orders-in-European-History/Hartmann-Heuser/p/book/9780415244404?_ga=undefined&srsltid=AfmBOoox71YrzcFy_inKNNmdcEvvZ_O-kRYlYLvjGTsJU3aP6opOhR0_|publisher=[[Routledge]]|isbn=978-0-415-24440-4}}
*{{cite book|last=Routledge|first=Michael|year=2002|orig-year=1999|chapter=Songs|editor-last=Riley-Smith|editor-first=Jonathan|title=The Oxford History of the Crusades|pages=90–110|publisher=[[Oxford University Press]]|url=https://global.oup.com/academic/product/the-oxford-history-of-the-crusades-9780192803122?cc=us&lang=en&|isbn=978-0-1928-0312-2}}
*{{cite book|last=Shachar|first=Uri Zvi|editor-last=Bale|editor-first=Anthony|editor-link=Anthony Bale|title=The Cambridge Companion to the Literature of the Crusades|url=https://www.cambridge.org/core/books/cambridge-companion-to-the-literature-of-the-crusades/26499BD90F47509267FE028A2B1786DF|series=Cambridge Companions to Literature|year=2019|chapter=Hebrew Crusade Literature in Its Latin and Arabic Contexts|pages=102–118|publisher=[[Cambridge University Press]]|isbn=978-1-1084-7451-1}}
*{{cite book|last=Sturtevant|first=Paul B.|editor1-last=Haydock|editor1-first=Nickolas|editor2-last=Risden|editor2-first=E. L.|title=Hollywood in the Holy Land: Essays on Film Depictions of the Crusades and Christian–Muslim Clashes|url=https://mcfarlandbooks.com/product/hollywood-in-the-holy-land/?srsltid=AfmBOopuiVahfQL__zOad3yo8W90X5MFpXKLekuv_eonEFN8t62-KLD4|year=2009|chapter=SaladiNasser: Nasser's Political Crusade in El Naser Salah Ad-Din|pages=123–146|publisher=[[McFarland & Company]]|isbn=978-0-7864-4156-3}}
*{{cite book|last=Thomson|first=John A.|year=1998|title=The Western Church in the Middle Ages|publisher=[[Edward Arnold (publisher)|Arnold]]|isbn=978-0-340-60118-1}}
*{{cite book|last=Thomson|first=Robert W.|author-link=Robert W. Thomson|year=2001|chapter=The Crusaders through Armenian Eyes|editor1-last=Laiou|editor1-first=Angeliki E.|editor1-link=Angeliki Laiou|editor2-last=Mottahedeh|editor2-first=Roy Parviz|editor2-link=Roy Mottahedeh|title=The Crusades from the Perspectives of Byzantium and the Muslim World|pages=71–82|publisher=[[Dumbarton Oaks Research Library]]|url=https://www.doaks.org/resources/publications/books/the-crusades-from-the-perspective-of-byzantium-and|isbn=978-0-88402-277-0}}
*{{cite book|last=Tibble|first=Steve|year=2025|orig-year=2024|title=Crusader Criminals: The Knights Who Went Rogue in the Holy Land|publisher=[[Yale University Press]]|url=https://yalebooks.yale.edu/book/9780300276077/crusader-criminals/|isbn=978-0-300-28429-4}}
*{{cite book|last=Tyerman|first=Christopher|author-link=Christopher Tyerman|year=2007|orig-year=2006|title=God's War: A History of the Crusades|publisher=[[Penguin Books]]|url=https://www.penguin.com.au/books/gods-war-9780141904313|isbn=978-0-1402-6980-2}}
*{{cite book|last=Tyerman|first=Christopher|year=2011|title=The Debate on the Crusades, 1099–2010|series=Issues in Historiography|url=https://manchesteruniversitypress.co.uk/9780719073212/|publisher=[[Manchester University Press]]|isbn=978-0-7190-7320-5}}
*{{cite book|last=Tyerman|first=Christopher|year=2019|title=The World of the Crusades: An Illustrated History|publisher=[[Yale University Press]]|url=https://yalebooks.yale.edu/book/9780300274219/the-world-of-the-crusades/|isbn=978-0-3002-1739-1}}
*{{cite journal|last=Wicks|first=Jared|date=September 1967|title=Martin Luther's Treatise on Indulgences|journal=[[Theological Studies (journal)|Theological Studies]]|volume=28|issue=3|pages=481–518|doi=10.1177/004056396702800302|url=https://journals.sagepub.com/doi/10.1177/004056396702800302|url-access=subscription}}
{{refend}}

== Further reading ==
{{refbegin|30em}}
*{{cite book |editor-last=Boas |editor-first=Adrian J. |title=The Crusader World |series=The Routledge Worlds|publisher=[[Routledge]] |year=2016 |url=https://www.routledge.com/The-Crusader-World/Boas/p/book/9780367867881?srsltid=AfmBOorm5GYT5Z81DEwE2mErWQYSS6IpqDDLE5_Na66HeDvtUAkUH_Ge|isbn=978-0-415-82494-1|ref=none}}
*{{cite book|last=Maier|first=Christophe T.|year=2010|title=Crusade Propaganda and Ideology: Model Sermons for the Preaching of the Cross|url=https://www.cambridge.org/core/books/crusade-propaganda-and-ideology/425DB24A44F76AD40CE6A0CD113627D5|publisher=[[Cambridge University Press]]|doi=10.1017/CBO9780511496554|isbn=978-0-5114-9655-4|ref=none}}
*{{cite book|editor-last=Nicholson|editor-first=Helen J|title=Palgrave Advances in the Crusades|publisher=[[Palgrave Macmillan]]|year=2005|doi=10.1057/9780230524095 |url=https://link.springer.com/book/10.1057/9780230524095|isbn=978-1-4039-1237-4|ref=none}}
*{{cite book|last=Polk|first=William R.|title=Crusade and Jihad: The Thousand-Year War Between the Muslim World and the Global North|series=The Henry L. Stimson Lectures Series|url=https://yalebooks.yale.edu/book/9780300222906/crusade-and-jihad/|publisher=[[Yale University Press]] |year=2018|isbn=978-0-3002-2290-6|ref=none}}
*{{cite book|last=Spencer|first=Stephen J.|title=Emotions in a Crusading Context, 1095-1291|url=https://academic.oup.com/book/41019|year=2019|publisher=Oxford University Press|isbn= 978-0-1988-3336-9|ref=none}}
*{{cite journal |last1=Tyerman|first1=Christopher|author-link=Christopher Tyerman|title=Were There Any Crusades in the Twelfth Century?|journal=The English Historical Review|date=1995|volume=110|issue=437|pages=553–577|jstor=578335|publisher=[[Oxford University Press]]|doi=10.1093/ehr/CX.437.553|ref=none|doi-access=free}}
{{refend}}

{{Crusader States}}
{{Middle Ages}}
{{History of Europe}}
{{History of the Catholic Church}}
{{Christian History}}
{{Christianity footer}}
{{Subject bar
|book1          = Crusades
|portal1        = Christianity
|portal2        = Islam
|portal3        = Middle Ages
|portal4        = History
|portal5        = Religion
|commons        = y
|commons-search = Category:Crusades
|wikt           = y
|wikt-search    = Crusade
|b              = y
|b-search       = Crusades
|q              = y
|q-search       = Crusades
|s              = y
|s-search       = Category:Crusades
|spoken         =
|v              = y
|v-search       = Crusades
|d              = y
}}

{{Authority control}}

[[Category:Crusades| ]]