View source for Constantius Chlorus

{{short description|Roman emperor from 305 to 306}}
{{Use dmy dates|date=July 2024}}
{{Infobox Roman emperor
| image        = Constantius Chlorus Ny Carlsberg Glyptotek IN836.jpg
| image_size   = 
| alt          = Male head statue
| caption      = Portrait usually identified with that of Constantius, [[Ny Carlsberg Glyptotek]]<ref>[http://laststatues.classics.ox.ac.uk/database/discussion.php?id=1178 http://laststatues.classics.ox.ac.uk, LSA-806 (J. Lenaghan)]</ref>
| succession   = [[Roman emperor]]
| moretext     = (in the [[Western Roman Empire|West]])
| reign        = 1 May 305 – 25 July 306 (with [[Galerius]] in the [[Eastern Roman Empire|East]])
| reign-type   = [[Augustus (title)|''Augustus'']]
| predecessor  = [[Maximian]]
| successor    = [[Severus II]] <small>(officially)</small><br/>[[Constantine I]] <small>(rebelled)</small>
| reign1       = 1 March 293 – 1 May 305
| reign-type1  = [[Caesar (title)|''Caesar'']]
| birth_date   = 31 March {{circa|250}}
| birth_place  = [[Moesia Superior]]
| death_date   = 25 July 306 (aged {{Circa|56}})
| death_place  = [[Eboracum]], [[Roman Britain]] (present-day [[York]], [[England]])
| burial_place = 
| spouse       = [[Helena, mother of Constantine I|Helena]] (disputed) and [[Flavia Maximiana Theodora|Theodora]]
| issue        = {{ubl|[[Constantine the Great]]|[[Flavius Dalmatius]]|[[Julius Constantius]]|[[Flavia Julia Constantia]]}}
| issue-link   = #Family
| issue-pipe   = among<br />others
| birth_name   = Flavius Constantius
| full name    = Marcus Flavius Valerius Constantius{{efn|This is the name given by [[Timothy D. Barnes]] and the ''[[Oxford Dictionary of Byzantium|ODB]]''.<ref name=barnes>{{cite book |last=Barnes |year=1982 |first=Timothy D. |title=The New Empire of Diocletian and Constantine |publisher=Harvard University Press |doi=10.4159/harvard.9780674280670 |place=Cambridge, MA |isbn=0-674-28066-0 |url=https://archive.org/details/barnes-new-empire|pages=4, 35}}</ref><ref name="ODB">{{Citation|last=Gregory|first=Timothy E.|author-link=Timothy E. Gregory|title=Constantius Chlorus|date=1991|url=https://archive.org/details/odb_20210521/page/524/mode/1up|work=[[Oxford Dictionary of Byzantium]]|editor-last=Kazhdan|editor-first=Alexander P.|editor-link=Alexander Kazhdan|publisher=Oxford University Press|doi=10.1093/acref/9780195046526.001.0001|isbn=978-0-19-504652-6|pages=524–525}}</ref> The ''[[Prosopography of the Later Roman Empire|PLRE]]'' omits the ''[[praenomen]]'', but does not elaborate.{{sfn|Jones|Martindale|Morris|p=227}} "[[Marcus (praenomen)|Marcus]]" appears in some inscriptions,<ref>[[Corpus Inscriptionum Latinarum|''CIL'' VIII]] [https://arachne.dainst.org/entity/2288152/image/2291096 608]</ref> but a few others use "[[Gaius (praenomen)|Gaius]]" instead.<ref>[[Inscriptiones Latinae Selectae|''ILS'']] I, [https://archive.org/details/inscriptioneslat01dessuoft/page/148 649]</ref> This may just be a confusion, as ordinary people "had become unaccustomed to varying praenomina, the last imperial dynasty to differentiate them having been that of [[Septimius Severus]]".<ref name="names">{{cite journal |last=Salway |year=1994 |first=Benet |title=What's in a Name? A Survey of Roman Onomastic Practice from c. 700 B.C. to A.D. 700 |journal=[[Journal of Roman Studies]] |volume=84 |pages=124–145|doi=10.2307/300873 |jstor=300873 |s2cid=162435434 |url=https://discovery.ucl.ac.uk/id/eprint/114213/1/SalwayJRS1994.pdf |author-link=Benet Salway }}</ref> Either way, ''praenomina'' were no longer used by this time, and emperors after Galerius stopped using them altogether.}}
| regnal name  = Imperator Caesar Marcus Flavius Constantius Augustus
| dynasty      = [[Constantinian dynasty|Constantinian]]
| mother       = [[Claudia (mother of Constantius)|Claudia]] (alleged)
| religion     = [[Religion in ancient Rome|Ancient Roman religion]]
}}

'''Flavius Valerius Constantius''' ({{circa|250}} – 25 July 306), also called '''Constantius&nbsp;I''', was a [[Roman emperor]] from 305 to 306. He was one of the four original members of the [[Tetrarchy]] established by [[Diocletian]], first serving as [[Caesar (title)|''caesar'']] from 293 to 305 and then ruling as [[Augustus (title)|''augustus'']] until his death. Constantius was also father of [[Constantine the Great]], the first Christian emperor of Rome. The nickname "Chlorus" ({{Langx|grc|[[:wikt:χλωρός|Χλωρός]]||the Pale}}) was first popularized by [[Byzantine Empire|Byzantine]]-era historians and not used during the emperor's lifetime.

As an [[Illyrian emperors|Illyrian soldier]] of humble origin, Constantius had a distinguished military career and rose to the top ranks of the army. Around 289, he set aside [[Helena (mother of Constantine)|Helena]], Constantine's mother, to marry a daughter of Emperor [[Maximian]], and in 293 was added to the imperial college by Maximian's colleague Diocletian. Assigned to rule [[Roman Gaul|Gaul]], Constantius defeated the usurper [[Carausius]] there and his successor [[Allectus]] in [[Roman Britain|Britain]], and campaigned extensively along the [[Limes Germanicus|Rhine frontier]], defeating the [[Alamanni]] and [[Franks]]. When the [[Diocletianic Persecution]] was announced in 303, Constantius ordered the demolition of churches but did not actively hunt down Christians in his domain.<ref name=odla> After his re-conquering of Roman Britain, he was given the title 'Redditor Lucis Aeternae', meaning 'The Restorer of Ethernal Light'.{{Citation|last1=Bond|first1=Sarah|title=Constantius I|url=https://research.vu.nl/files/248046167/Oxford_Dictionary_of_Late_Antiquity_cosmology.pdf|work=The Oxford Dictionary of Late Antiquity|volume=|pages=|year=2018|editor-last=Nicholson|editor-first=Oliver|publisher=Oxford University Press|language=en|doi=10.1093/acref/9780198662778.001.0001|isbn=978-0-19-866277-8|quote=the nickname Chlorus (Green) is not older than the 6th century|access-date=25 August 2020|last2=Nicholson|first2=Oliver}}</ref> Upon becoming senior emperor in May 305, Constantius launched a successful punitive campaign against the [[Picts]] beyond the [[Antonine Wall]].<ref>W.S. Hanson [http://ads.ahds.ac.uk/catalogue/adsdata/PSAS_2002/pdf/vol_109/109_140_150.pdf "Roman campaigns north of the Forth-Clyde isthmus: the evidence of the temporary camps"] {{Webarchive|url=https://web.archive.org/web/20180905175614/http://ads.ahds.ac.uk/catalogue/adsdata/PSAS_2002/pdf/vol_109/109_140_150.pdf |date=5 September 2018 }}</ref> He died suddenly at [[Eboracum]] ([[York]]) in July the following year.

After Constantius's death, the army, perhaps at his own instigation, immediately acclaimed his son [[Constantine the Great|Constantine]] as emperor. This act contributed to the collapse of the Diocletianic tetrarchy, sparking a series of civil wars which only ended when Constantine finally united the whole Roman Empire under his rule in 324. According to the ''[[Oxford Classical Dictionary]]'', "Constantinian propaganda bedevils assessment of Constantius, yet he appears to have been an able general and a generous ruler".<ref>{{Cite book |last=Davis |first=Raymond |title=Oxford Classical Dictionary |chapter-url=http://oxfordre.com/classics/view/10.1093/acrefore/9780199381135.001.0001/acrefore-9780199381135-e-1790 |chapter=Constantius I, Flavius Valerius, Roman emperor |date=22 December 2015 |publisher=Oxford University Press |doi=10.1093/acrefore/9780199381135.013.1790|isbn=978-0-19-938113-5 }}</ref> His descendants, the [[Constantinian dynasty]], ruled the Empire until the death of his grandson [[Julian (emperor)|Julian]] in 363.

==Life==

===Early career===
Constantius's birthday was 31 March; the year is unknown, but his career and the age of his eldest son imply a date no later than c. 250.<ref name=barnes>{{cite book |last=Barnes |year=1982 |first=Timothy D. |title=The New Empire of Diocletian and Constantine |publisher=Harvard University Press |doi=10.4159/harvard.9780674280670 |place=Cambridge, MA |isbn=0-674-28066-0 |url=https://archive.org/details/barnes-new-empire|pages=4, 35}}</ref> Constantius was an [[Illyrians|Illyrian]].{{sfn|Odahl|2010|p=40}}<ref name="Murray221">{{harvnb|Murray|1999|p=221}}</ref>{{efn|On the other hand, [[Timothy Barnes (classicist)|Timothy Barnes]] argues that when ancient writers used the words [[Illyria|Illyricum]] and [[Thrace]]/[[Thracians]] to describe where Constantius came from, they were speaking of broad geographic terms rather than precise origins.{{sfn|Barnes|2011|p=[https://books.google.com/books?id=MwIiAgAAQBAJ&pg=PA30 30]}}}} He was born in [[Moesia Superior]] (later [[Dacia Ripensis]]),<ref name="ODB">{{Citation|last=Gregory|first=Timothy E.|author-link=Timothy E. Gregory|title=Constantius Chlorus|date=1991|url=https://archive.org/details/odb_20210521/page/524/mode/1up|work=[[Oxford Dictionary of Byzantium]]|editor-last=Kazhdan|editor-first=Alexander P.|editor-link=Alexander Kazhdan|publisher=Oxford University Press|doi=10.1093/acref/9780195046526.001.0001|isbn=978-0-19-504652-6|pages=524–525}}</ref>{{sfn|Barnes|2011|p=[https://books.google.com/books?id=MwIiAgAAQBAJ&pg=PA30 30]}} a [[Roman province#Late Antiquity|Roman province]] on the south bank of the [[Middle Danube]]. According to the unreliable ''[[Historia Augusta]]'' he was the son of Eutropius, a [[nobility|nobleman]] from the province of [[Moesia Superior]], and [[Claudia (mother of Constantius)|Claudia]], a niece of the emperors [[Claudius Gothicus]] and [[Quintillus]].<ref>''[[Historia Augusta]]'', ''Life of Claudius'' [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Historia_Augusta/Claudius*.html#13 13]. [[LacusCurtius]].</ref> The same source also gives Claudius the nomina "[[Flavia gens|Flavius]] [[Valeria gens|Valerius]]" to strengthen his connection to Constantius.<ref>''[[Historia Augusta]]'', ''Life of Claudius'' [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Historia_Augusta/Claudius*.html#13 1 (note 1)]. [[LacusCurtius]].</ref> Modern historians suspect this maternal connection to be a genealogical [[Lie#Fabrication|fabrication]] created by his son [[Constantine I (emperor)|Constantine I]],<ref>Southern, p. 172</ref> and that his family was of humble origins.{{sfn|Jones|Martindale|Morris|p=227}}<ref name="ODB" />{{efn|His family probably adopted the name "Flavius" after being granted citizenship by one of these emperors, as it was common for "new Romans" to adopt the names of their former masters.<ref name="names"/>}} Constantine probably sought to dissociate his father's background from the memory of Maximian.<ref name=":0">{{Citation|last1=Bond|first1=Sarah|title=Constantius I|url=https://research.vu.nl/files/248046167/Oxford_Dictionary_of_Late_Antiquity_cosmology.pdf|work=The Oxford Dictionary of Late Antiquity|year=2018|editor-last=Nicholson|editor-first=Oliver|publisher=Oxford University Press|language=en|doi=10.1093/acref/9780198662778.001.0001|isbn=978-0-19-866277-8|access-date=25 August 2020|last2=Nicholson|first2=Oliver|url-access=}}</ref>

[[File:Bronze-Flavia Maximiana Theodora-trier RIC 65.jpg|thumb|250px|Coin showing the ''Augusta'' Flavia Maximiana Theodora, Constantius's second wife, with the goddess ''[[Pietas (goddess)|Pietas]]'' on the reverse]]
Constantius was a member of the ''[[Protectores Augusti Nostri]]'' under the emperor [[Aurelian]] and fought in the east against the secessionist [[Palmyrene Empire]].<ref name="Potter, pg. 288">Potter, p. 288</ref> While the claim that he had been made a ''[[dux]]'' under the emperor [[Marcus Aurelius Probus|Probus]] is probably a fabrication,{{sfn|Jones|Martindale|Morris|p=228}}<ref>''[[Historia Augusta]]'', ''Life of Probus'' [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Historia_Augusta/Probus*.html#22 22:3]. [[LacusCurtius]].</ref> he certainly attained the rank of ''[[tribunus]]'' within the army, and during the reign of [[Carus]] he was raised to the position of ''[[praeses]]'', or governor, of the province of [[Dalmatia (Roman province)|Dalmatia]].<ref>Odahl, Charles Matson. Constantine and the Christian Empire. New York: Routledge, 2004. p. 16</ref> It has been conjectured that he switched allegiances to support the claims of the future emperor [[Diocletian]] just before Diocletian defeated [[Carinus]], the son of Carus, at the [[Battle of the Margus]] in July 285.<ref>Potter, p. 280</ref>

In 286, Diocletian elevated a military colleague, [[Maximian]], to the throne as co-emperor of the western provinces,<ref name="Southern, pg. 142">Southern, p. 142</ref> while Diocletian took over the eastern provinces, beginning the process that would eventually see the division of the [[Roman Empire]] into two halves, a [[Western Roman Empire|Western]] and an [[Byzantine Empire|Eastern]] portion. By 288, his period as governor now over, Constantius had been made [[praetorian prefect]] in the west under Maximian.<ref name="DiMaio, Constantine I Chlorus"/> Throughout 287 and into 288, Constantius, under the command of Maximian, was involved in a war against the [[Alamanni]], carrying out attacks on the territory of the [[barbarian]] tribes across the [[Rhine]] and [[Danube]] rivers.<ref name="Southern, pg. 142">Southern, p. 142</ref> To consolidate the ties between himself and Emperor Maximian, Constantius married the emperor's daughter, [[Flavia Maximiana Theodora|Theodora]].<ref name="Potter, pg. 288"/>

===Elevation as Caesar===
[[File:Argenteus-Constantius I-antioch RIC 033a.jpg|250px|thumb|On the reverse of this [[argenteus]] struck in [[Antioch]] under Constantius Chlorus, the [[tetrarchy|tetrarchs]] are sacrificing to celebrate a victory against the [[Sarmatia]]ns.]]
By 293, [[Diocletian]], conscious of the ambitions of his co-emperor for his new son-in-law, allowed Maximian to promote Constantius in a new power sharing arrangement known as the [[Tetrarchy]]. The eastern and western provinces would each be ruled by an [[Augustus (honorific)|''augustus'']], supported by a [[Caesar (title)|''caesar'']]. Both ''caesares'' had the right of succession once the ruling ''augustus'' died.<ref name="Southern, pg. 145">Southern, p. 145</ref>

At [[Mediolanum]] ([[Milan]]) on 1 March 293, Constantius was formally appointed as Maximian's ''caesar''.<ref>Birley, p. 382</ref> He adopted Diocletian's ''[[Roman naming conventions|nomen]]'' (family name) "Valerius", and, being equated with Maximian, also took on "Herculius".<ref name="Southern, pg. 147">Southern, p. 147</ref>  His given command consisted of [[Gaul]], [[Roman Britain|Britannia]] and possibly [[Hispania]]. [[Diocletian]], the eastern ''augustus'', in order to keep the balance of power in the ''imperium'',<ref name="Southern, pg. 145">Southern, p. 145</ref> elevated [[Galerius]] as his ''caesar'', possibly on 21 May 293 at [[Philippopolis (Thrace)|Philippopolis]] ([[Plovdiv]]).<ref name="Potter, pg. 288">Potter, p. 288</ref> Constantius was the more senior of the two ''caesares'', and on official documents he always took precedence, being mentioned before Galerius.<ref name="Southern, pg. 147">Southern, p. 147</ref> Constantius's capital was to be located at [[Augusta Treverorum]] ([[Trier]]).<ref>{{Citation|last1=Woolf|first1=Greg|title=The Cambridge Illustrated History of the Roman World|year=2003|editor-last=Nicholson|editor-first=Oliver|publisher=Cambridge University Press|url=https://books.google.com/books?id=qO54sAEvDL4C&pg=PA224|isbn=9780521827751|page=224}}</ref>

Constantius's first task on becoming ''caesar'' was to deal with the [[Roman usurper]] [[Carausius]] who had declared himself emperor in Britannia and northern Gaul in 286.<ref name="Potter, pg. 288"/>  In late 293, Constantius defeated the forces of Carausius in Gaul, capturing Bononia ([[Boulogne-sur-Mer]]).<ref>Birley, p. 385</ref> Carausius was then assassinated by his ''[[rationalis]]'' (finance officer) [[Allectus]], who assumed command of the British provinces until his death in 296.<ref>{{cite encyclopedia | last = Schmitz | first = Leonhard | author-link = Leonhard Schmitz | title = Allectus | editor = William Smith | editor-link = William Smith (lexicographer) | encyclopedia = [[Dictionary of Greek and Roman Biography and Mythology]] | volume = 1 | pages = 132 | publisher = [[Little, Brown and Company]] | location = Boston | year = 1867 | url = http://quod.lib.umich.edu/cgi/t/text/pageviewer-idx?c=moa;cc=moa;idno=acl3129.0001.001;q1=demosthenes;size=l;frm=frameset;seq=147}}</ref>

Constantius spent the next two years neutralising the threat of the [[Franks]] who were the allies of Allectus,<ref name="Southern, pg. 149">Southern, pg. 149</ref> as northern Gaul remained under the control of the British usurper until at least 295.<ref>Birley, p. 387</ref> He also battled against the [[Alamanni]], achieving some victories at the mouth of the [[Rhine]] in 295.<ref>Birley, pp. 385–386</ref> Administrative concerns meant he made at least one trip to Italy during this time as well.<ref name="Southern, pg. 149"/> Only when he felt ready (and only when Maximian finally came to relieve him at the Rhine frontier)<ref name="Southern, pg. 150">Southern, p. 150</ref> did he assemble two invasion fleets with the intent of crossing the [[English Channel]]. The first was entrusted to [[Julius Asclepiodotus]], Constantius's long-serving [[Praetorian prefect]], who sailed from the mouth of the [[Seine]], while the other, under the command of Constantius himself, was launched from his base at Bononia.<ref>Birley, p. 388</ref> The fleet under Asclepiodotus landed near the [[Isle of Wight]], and his army encountered the forces of Allectus, resulting in the defeat and death of the usurper.<ref>[[Aurelius Victor]], ''Liber de Caesaribus'', [http://www.thelatinlibrary.com/victor.caes.html#39 39]</ref> Constantius in the meantime occupied [[Londinium]] ([[London]]),<ref>Potter, p. 292</ref> saving the city from an attack by [[Franks|Frankish]] mercenaries who were now roaming the province without a paymaster. Constantius massacred all of them.<ref name="Southern, pg. 150">Southern, p. 150</ref>
[[File:Bust of Constantius Chlorus - Altes Museum - Berlin - Germany 2017 (2).jpg|alt=Portrait head of Constantius Chlorus.|thumb|Portrait head of Tetrarch, most likely Constantius Chlorus.<ref>[http://laststatues.classics.ox.ac.uk/database/discussion.php?id=1227 http://laststatues.classics.ox.ac.uk, LSA-855 ((K. Dahmen, M. Maischberger, C. Blümel)]</ref>]]
Constantius remained in Britannia for a few months, replaced most of Allectus's officers, and the British provinces were probably at this time subdivided along the lines of Diocletian's other administrative reforms of the Empire.<ref>Birley, p. 393</ref> The result was the division of [[Britannia Superior]] into [[Maxima Caesariensis]] and [[Britannia Prima]], while [[Flavia Caesariensis]] and [[Britannia Secunda]] were carved out of [[Britannia Inferior]]. He also restored [[Hadrian's Wall]] and its forts.<ref>Birley, p. 405</ref>

Later in 298, Constantius fought in the [[Battle of Lingones]] ([[Langres]]) against the [[Alemanni]]. He was shut up in the city, but was relieved by his army after six hours and defeated the enemy.<ref>Eutropius, ''Breviarum'' {{usurped|1=[https://web.archive.org/web/20031222152525/http://www.forumromanum.org/literature/eutropius/trans9.html#23 9.23]}}</ref> He [[Battle of Vindonissa|defeated them again at Vindonissa]]<ref>[http://www.unrv.com/military/battles-of-the-third-century.php UNRV History: Battle of the Third Century AD]</ref> thereby strengthening the defences of the [[Rhine]] frontier. In 300, he fought against the [[Franks]] on the Rhine frontier,<ref name="Southern, pg. 152">Southern, pg. 152</ref> and as part of his overall strategy to buttress the frontier, Constantius settled the Franks in the deserted parts of [[Gaul]] to repopulate the devastated areas.<ref>Birley, p. 373</ref>  Nevertheless, over the next three years the Rhine frontier continued to occupy Constantius's attention.<ref name="Southern, pg. 152"/>

From 303 – the beginning of the [[Diocletianic Persecution]] – Constantius began to enforce the imperial edicts dealing with the [[Persecution of Christians in the Roman Empire|persecution of Christians]], which ordered the destruction of [[Church (building)|churches]].<ref name=":0">{{Citation|last1=Bond|first1=Sarah|title=Constantius I|url=https://research.vu.nl/files/248046167/Oxford_Dictionary_of_Late_Antiquity_cosmology.pdf|work=The Oxford Dictionary of Late Antiquity|year=2018|editor-last=Nicholson|editor-first=Oliver|publisher=Oxford University Press|language=en|doi=10.1093/acref/9780198662778.001.0001|isbn=978-0-19-866277-8|access-date=25 August 2020|last2=Nicholson|first2=Oliver|url-access=}}</ref> The campaign was avidly pursued by [[Galerius]], who noticed that Constantius was well-disposed towards the [[Christians]], and who saw it as a method of advancing his career prospects with the aging Diocletian.<ref>Potter, p. 338</ref> Of the four Tetrarchs, Constantius made the least effort to implement the decrees in the western provinces that were under his direct authority,<ref>Potter, p. 339; Southern, p. 168</ref> limiting himself to knocking down a handful of churches.<ref name="DiMaio, Constantine I Chlorus">DiMaio, ''Constantine I Chlorus''</ref> [[Eusebius]] denied that Constantius destroyed Christian buildings, but [[Lactantius]] records that he did.<ref name=":0" />

===Accession as Augustus and death===
[[File:Constantius I capturing London after defeating Allectus Beaurains hoard.jpg|thumb|Copy of a medal of Constantius I capturing [[Londinium]] (inscribed as LON) after defeating [[Allectus]]. The original was part of the [[Beaurains Treasure]] from [[Arras]], France.]]
Between 303 and 305, Galerius began maneuvering to ensure that he would be in a position to take power from Constantius after the death of Diocletian.<ref>Potter, p. 344</ref> In 304, Maximian met with Galerius, probably to discuss the succession issue and Constantius either was not invited or could not make it due to the situation on the Rhine.<ref name="Southern, pg. 152"/> Although prior to 303 there appeared to be tacit agreement among the Tetrarchs that Constantius's son [[Constantine I|Constantine]] and Maximian's son [[Maxentius]] were to be promoted to the rank of ''caesar'' once Diocletian and Maximian had resigned the purple,<ref>Potter, p. 340</ref> by the end of 304 Galerius had convinced Diocletian (who in turn convinced Maximian) to appoint Galerius's nominees [[Severus II|Severus]] and [[Maximinus Daza|Maximinus]] as ''caesares''.<ref name="Southern, pg. 152"/>

Diocletian and Maximian stepped down as co-emperors on 1 May 305, possibly due to Diocletian's poor health.<ref name="DiMaio, Constantine I Chlorus"/> Before the assembled armies at Mediolanum, Maximian removed his purple cloak and handed it to Severus, the new ''caesar'', and proclaimed Constantius as ''augustus''. The same scene played out at [[Nicomedia]] ([[İzmit]]) under the authority of Diocletian.<ref>Potter, p. 342</ref> Constantius, notionally the senior emperor, ruled the western provinces, while Galerius took the eastern provinces. Constantine, disappointed in his hopes to become a ''caesar'', fled the court of Galerius after Constantius had asked Galerius to release his son as Constantius was ill.<ref>Southern, p. 169</ref> Constantine joined his father's court at the coast of Gaul, just as he was preparing to campaign in Britain.<ref>Southern, p. 170; Eutropius, ''Breviarum'' {{usurped|1=[https://web.archive.org/web/20031019084032/http://www.forumromanum.org/literature/eutropius/trans10.html#1 10.1]}}; Aurelius Victor, ''[[Epitome de Caesaribus]]'' [http://www.roman-emperors.org/epitome.htm 39]; Zosimus, ''Historia Nova'' [http://www.tertullian.org/fathers/zosimus02_book2.htm 2]</ref>

In 305, Constantius crossed over into Britain, travelled to the far north of the island and launched a military expedition against the [[Picts]], claiming a victory against them and the title ''Britannicus Maximus II'' by 7 January 306.<ref>Birley, p. 406</ref>  After retiring to [[Eboracum]] ([[York]]) for the winter, Constantius had planned to continue the campaign, but on 25 July 306 he died.<ref>''Consularia Constantinopolitana'' 306, in ''[[Monumenta Germaniae Historica]]'' ant. 11: ''[[iarchive:chronicaminorasa09momm/page/231/mode/1up|Chronica Minora]]'' Vol. 1 ([[Theodor Mommsen]] ed., 1892) p. 231. {{ISBN|978-0656631308}}</ref> As he was dying, Constantius recommended his son to the army as his successor;<ref>Potter, pg. 346</ref> consequently, [[Constantine the Great|Constantine]] was declared emperor by the legions at York.<ref>Eutropius, ''Breviarum'' {{usurped|1=[https://web.archive.org/web/20031019084032/http://www.forumromanum.org/literature/eutropius/trans10.html#1 10.1–2]}}</ref>

==Family==
Constantius was either married to, or was in concubinage with, [[Helena of Constantinople|Helena]], who was probably from [[Nicomedia]] in Asia Minor.<ref>[[Eutropius (historian)|Eutropius]], ''Breviarum'' {{usurped|1=[https://web.archive.org/web/20031222152525/http://www.forumromanum.org/literature/eutropius/trans9.html#22 9.22]}}; [[Zosimus (historian)|Zosimus]], ''Historia Nova'' [http://www.tertullian.org/fathers/zosimus02_book2.htm 2]; ''Exerpta Valesiana'' [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Excerpta_Valesiana/1*.html#2a 1.2]</ref> They had one son, the future emperor [[Constantine the Great]].

In 289, political developments forced him to divorce [[Helena (empress)|Helena]]. He married [[Flavia Maximiana Theodora|Theodora]], [[Maximian]]'s daughter. They had six children:{{sfn|Jones|Martindale|Morris|p=228}}

*[[Flavius Dalmatius]]
*[[Julius Constantius]]
*[[Hannibalianus|Flavius Hannibalianus]]
*[[Flavia Julia Constantia]]
*[[Anastasia (sister of Constantine I)|Anastasia]], married to [[Bassianus (executed by Constantine)|Bassianus]]
*[[Eutropia (sister of Constantine I)|Eutropia]]
The name of Anastasia ({{Langx|grc-x-koine|Ἀναστασία|lit=resurrection|translit=Anastasía}}) may indicate a sympathy with Christian or Jewish culture.<ref name="ODB" />

===Family tree===
{{see also|Constantinian dynasty}}

{{Chart top|width=100%|collapsed=auto}}
Emperors are shown with a rounded-corner border with their dates as [[Augusti]], names with a thicker border appear in both sections

'''1: Constantine's parents and half-siblings'''
{{Tree chart/start|align=center}}
{{tree chart| | | | | | |CGOTH|CGOTH={{ubl|[[Maximian]]|286–305|''adoptive father''}}|boxstyle_CGOTH=border:2px solid; border-radius:1em}}
{{tree chart| | | | | | | |Q|}}
{{tree chart| | |HELEN|y|CCHLO|y|THEO1|HELEN=[[Helena, mother of Constantine I|Helena]]|boxstyle_HELEN=border:2px solid|CCHLO={{ubl|Constantius Chlorus|250–306}}|boxstyle_CCHLO=border:2px solid; border-radius:1em|THEO1=[[Flavia Maximiana Theodora]]}}
{{tree chart| | | | | |!| | | |)|-|v|-|v|-|-|-|v|-|-|-|-|-|v|-|.| | | | | }}
{{tree chart| | | | |CONST| |FLAVD|!|HANN1| |CONS2|y|LICI1|!|ANAST|~|BASSI|CONST={{ubl|'''Constantine I'''|306–337}}|boxstyle_CONST=border:3px solid; border-radius:1em|FLAVD=[[Flavius Dalmatius]]|HANN1=Hannibalianus|CONS2=[[Flavia Julia Constantia]]|LICI1={{ubl|[[Licinius]]|308–324}}|boxstyle_LICI1=border:2px solid; border-radius:1em|ANAST=[[Anastasia (sister of Constantine I)|Anastasia]]|BASSI=[[Bassianus (executed by Constantine)|Bassianus]]}}
{{tree chart| |,|-|-|-|-|-|-|-|'| |!| | | | | | | |!| | | |!}}
{{tree chart| |!| | | | |GALL1|y|JULIC|y|BASIL| |LICI2| |EUTR2|y|NEPO1|GALL1=[[Galla (wife of Julius Constantius)|Galla]]|JULIC=[[Julius Constantius]]|BASIL=[[Basilina]]|LICI2=[[Licinius II]]|EUTR2=[[Eutropia (sister of Constantine I)|Eutropia]]|NEPO1=Virius Nepotianus}}
{{tree chart| |!| | | | | | | |!| | | |!| | | | | | | | | | | |!}}
{{tree chart|HANN2|~|CONS6|~|GALLU| |JULIA|~|HELE2| | | | | |NEPO2|HANN2=[[Hannibalianus]]|boxstyle_HANN2=border:3px solid|CONS6=[[Constantina]]|boxstyle_CONS6=border:3px solid|GALLU=[[Constantius Gallus]]|boxstyle_GALLU=border:3px solid|JULIA={{ubl|[[Julian (emperor)|Julian]]|360–363}}|boxstyle_JULIA=border:3px solid; border-radius:1em|HELE2=[[Helena (wife of Julian)|Helena]]|boxstyle_HELE2=border:3px solid|NEPO2=[[Nepotianus]]}}
{{tree chart/end}}
{{break}}
'''2: Constantine's children'''
{{Tree chart/start|align=center}}
{{tree chart|MINER|y|CONST|y|FAUS1|MINER=[[Minervina]]|CONST={{ubl|'''Constantine I'''|306–337}}|boxstyle_CONST=border:3px solid; border-radius:1em|FAUS1=[[Fausta]]}}
{{tree chart| | | |!| | | |)|-|v|-|v|-|v|-|-|-|-|-|.|}}
{{tree chart| | |CRISP| |CONS3|!|CONS5|!|HANN2|~|CONS6|~|GALLU|CRISP=[[Crispus]]|CONS3={{ubl|[[Constantine II (emperor)|Constantine II]]|337–340}}|boxstyle_CONS3=border:2px solid; border-radius:1em|CONS5={{ubl|[[Constans]]|337–350}}|boxstyle_CONS5=border:2px solid; border-radius:1em|HANN2=[[Hannibalianus]]|boxstyle_HANN2=border:3px solid|CONS6=[[Constantina]]|boxstyle_CONS6=border:3px solid|GALLU=[[Constantius Gallus]]|boxstyle_GALLU=border:3px solid}}
{{tree chart| | | | | | | | | |!| | | |!}}
{{tree chart| | | | |FAUS2|y|CONS4| |HELE2|~|JULIA|FAUS2=[[Faustina (wife of Constantius II)|Faustina]]|CONS4={{ubl|[[Constantius II]]|337–361}}|boxstyle_CONS4=border:2px solid; border-radius:1em|JULIA={{ubl|[[Julian (emperor)|Julian]]|360–363}}|boxstyle_JULIA=border:3px solid;  border-radius:1em|HELE2=[[Helena (wife of Julian)|Helena]]|boxstyle_HELE2=border:3px solid}}
{{tree chart| | | | | | | |!}}
{{tree chart| | |GRATI|~|CONS7|GRATI={{ubl|[[Gratian]]|367–383}}|boxstyle_GRATI=border:2px solid; border-radius:1em|CONS7=[[Constantia (wife of Gratian)|Constantia]]}}
{{Tree chart/end}}
{{Chart bottom}}

{{Constantinian dynasty family tree}}

==Legend==

===Christian legends===
As the father of Constantine, a number of Christian legends have grown up around Constantius. Eusebius's ''Life of Constantine'' claims that Constantius was himself a Christian, although he pretended to be a pagan, and while Caesar under Diocletian, took no part in the Emperor's persecutions.<ref>[[Eusebius of Caesarea|Eusebius]], ''Vita Constantini'' [http://www.ccel.org/ccel/schaff/npnf201.iv.vi.i.xiii.html 1.13–18]</ref> It was claimed that his first wife, [[Helena of Constantinople|Helena]], found the [[True Cross]].{{Citation needed|date=July 2019}}

===British legends===
Constantius's activities in Britain were remembered in [[Welsh legends|medieval Welsh legend]], which frequently confused his family with that of [[Magnus Maximus]], who also was said to have wed a [[Saint Elen]] and sired a son named Constantine while in Britain. [[Henry of Huntingdon]]'s ''History of the English'' identified Constantius's wife Helen as British<ref>[[Henry of Huntingdon]], ''Historia Anglorum'' [[s:History of the English/Book 1#37|1.37]]</ref> and [[Geoffrey of Monmouth]] repeated the claim in his 1136 ''[[Historia Regum Britanniae|History of the Kings of Britain]]''. Geoffrey related that Constantius was sent to Britain by the [[Roman Senate|Senate]] after [[Julius Asclepiodotus|Asclepiodotus]] (here a British king) was overthrown by [[King Cole|Coel]] of [[Camulodunum|Colchester]]. Coel submitted to Constantius and agreed to pay tribute to Rome, but died only eight days later. Constantius married his daughter Helena and became [[king of Britain]]. He and Helena had a son, Constantine, who succeeded to the throne of Britain when his father died at [[Eboracum|York]] eleven years later.<ref>[[Geoffrey of Monmouth]], ''[[Historia Regum Britanniae]]'' [[Wikisource:History of the Kings of Britain/Book 5#6|5.6]]</ref> These accounts have no historical validity: Constantius had divorced Helena before he went to Britain.{{sfn|Barnes|1981|pp=3–4}}

Similarly, the ''[[Historia Brittonum|History of the Britons]]'' traditionally ascribed to [[Nennius]]<ref name=mommy>[[Nennius]] ({{abbr|attrib.|Traditional attribution}}). [[Theodor Mommsen]] ({{abbr|ed.|Editor}}). [[s:la:Historia Brittonum|''Historia Brittonum''.]] Composed after AD&nbsp;830. {{in lang|la}} Hosted at [[s:la:Main Page|Latin Wikisource]].</ref> claims the inscribed tomb of "Constantius the Emperor" was still present in the 9th century in the Roman fort of [[Segontium]] (near present-day [[Caernarfon]], in [[North Wales]]).<ref name=shusher>Newman, John Henry &&nbsp;al. [http://www.mocavo.co.uk/Lives-of-the-English-Saints-St-Gilbert-Prior-of-Sempringham-Volume-3/527392/459 ''Lives of the English Saints: St. German, Bishop of Auxerre'', Ch.&nbsp;X: "Britain in 429, A.&nbsp;D.",<!--sic--> p.&nbsp;92.] {{Webarchive|url=https://web.archive.org/web/20160321234154/http://www.mocavo.co.uk/Lives-of-the-English-Saints-St-Gilbert-Prior-of-Sempringham-Volume-3/527392/459 |date=21 March 2016 }} James Toovey (London), 1844.</ref> David Nash Ford credited the monument to Constantine, the supposed son of Magnus Maximus and Elen, who was said to have ruled over the area prior to the [[Irish invasions of Wales|Irish invasions]].<ref name=nashford>Ford, David Nash. "[http://www.britannia.com/history/ebk/articles/nenniuscities.html The 28 Cities of Britain] {{Webarchive|url=https://web.archive.org/web/20160415120312/http://www.britannia.com/history/ebk/articles/nenniuscities.html |date=2016-04-15 }}" at Britannia. 2000.</ref>

==Notes==
{{notelist}}

==Sources==

===Ancient sources===
{{Refbegin|30em}}
*[[Aurelius Victor]], [http://www.roman-emperors.org/epitome.htm ''Epitome de Caesaribus'']
* {{Cite book|translator-first=H. W.|translator-last=Bird|title=Liber de Caesaribus of Sextus Aurelius Victor|year=1994|publisher=Liverpool University Press|url=https://archive.org/details/aurelius-victor-h.-w.-bird-de-caesaribus-1994-liverpool/mode/2up|ref = {{harvid|Bird|1994}}}}
*[[Zosimus (historian)|Zosimus]], [http://www.tertullian.org/fathers/zosimus02_book2.htm ''Historia Nova'']
{{Refend}}

===Modern sources===
{{Refbegin|30em}}
* {{Cite book |last=Barnes |first=Timothy David |title=Constantine and Eusebius |date=1981 |publisher=Harvard University Press |isbn=0-674-16530-6 |location=Cambridge, Mass. |oclc=7459753}}
*{{cite book |last=Barnes |year=2011 |first=Timothy |title=Constantine: Dynasty, Religion and Power in the Later Roman Empire |publisher=Wiley-Blackwell |place=Oxford |isbn=978-1-405-11727-2}}
* {{citation | last = Birley | first = Anthony | title =The Roman Government in Britain| publisher = Oxford University Press | year = 2005 | isbn = 978-0-19-925237-4 | ref=no}}
* DiMaio, Robert, "[https://web.archive.org/web/20220321061813/http://www.roman-emperors.org/chlorus.htm Constantius I Chlorus (305–306 A.D.)]", ''De Imperatoribus Romanis'', 1996.
* {{cite book |last=Jones |year=1971 |first=A.H.M. |author2=J.R. Martindale |author3=J. Morris |title=[[Prosopography of the Later Roman Empire]]|volume=1|publisher=Cambridge University Press |isbn=0-521-07233-6|chapter-url=https://archive.org/details/prosopography-later-roman-empire/PLRE-I/page/227/mode/1up|chapter=Fl. Val. Constantius 12|name-list-style=amp |author-link=A. H. M. Jones |author-link2=John Robert Martindale |author-link3=John Morris (historian) |ref={{sfnref|Jones|Martindale|Morris}} }}
*{{cite book |last1=Kuhoff |first1=Wolfgang |title=Diokletian und die Epoche der Tetrarchie. Das römische Reich zwischen Krisenbewältigung und Neuaufbau (284–313 n. Chr.) |date=2001 |location=Frankfurt am Main |publisher=Peter Lang}}
*{{cite book |last1=Murray |first1=Alexander |title=From Roman to Merovingian Gaul: A Reader |date=1999 |publisher=University of Toronto Press |isbn=1442604131 |url=https://books.google.com/books?id=jBZ2M2qYcoMC}}
*{{cite book |last1=Odahl |first1=Charles |title=Constantine and the Christian Empire |date=2010 |publisher=Routledge |isbn=978-1136961281 |url=https://books.google.com/books?id=770uCgAAQBAJ}}
* Potter, David Stone, ''The Roman Empire at Bay, AD 180–395'', Routledge, 2004
* {{wikicite |reference=[[Otto Seeck|Seeck, Otto]], "[[s:de:RE:Constantius 1|Constantius 1]]", ''[[Realencyclopädie der classischen Altertumswissenschaft]]'', [[iarchive:PaulysReal-encyclopadieDerClassischenAltertumswissenschaftVolume7/page/n261/mode/2up|volume 7]] (IV.1), Metzlerscher Verlag (Stuttgart, 1900), columns 1040–1043.|ref={{sfnref|Seeck}} }}
* Southern, Pat. ''The Roman Empire from Severus to Constantine'', Routledge, 2001
{{Refend}}

==References==
{{Reflist}}

{{s-start}}
{{s-hou | [[Constantinian dynasty]] | 31 March | c. 250 | 25 July | 306 }}
{{s-reg}}
{{s-bef |before= [[Maximian]] }}
{{s-ttl |title = [[List of Roman emperors|Roman emperor]] |years= 305–306 |with=[[Galerius]] (east)}}
{{s-aft |after = [[Severus II]] <small>(west)</small>|after2=[[Constantine I]] <small>(west)</small>|after3=[[Galerius]] <small>(east)</small>}}
{{s-off}}
{{s-bef | before = [[Diocletian|Diocletian Augustus]]|before2=[[Maximian|Maximian Augustus]] }}
{{s-ttl | title  = [[List of Roman consuls|Roman consul]]| years = 294 | regent1 = [[Galerius|Galerius Augustus]] }}
{{s-aft | after  = [[Nummius Tuscus]]|after2=[[Gaius Annius Anullinus|G. Annius Anullinus]] }}
{{s-bef | before = [[Nummius Tuscus]]|before2=[[Gaius Annius Anullinus|G. Annius Anullinus]] }}
{{s-ttl | title  = [[List of Roman consuls|Roman consul]] II| years = 296 | regent1 = [[Diocletian|Diocletian Augustus]] }}
{{s-aft | after  = [[Maximian|Diocletian Augustus]]|after2=[[Galerius|Galerius Augustus]] }}
{{s-bef | before = [[Diocletian|Diocletian Augustus]]|before2=[[Maximian|Maximian Augustus]] }}
{{s-ttl | title  = [[List of Roman consuls|Roman consul]] III| years = 300 | regent1 = [[Galerius|Galerius Augustus]] }}
{{s-aft | after  = [[Titus Flavius Postumius Titianus|T. Flavius Postumius Titianus]]|after2=Virius Nepotianus }}
{{s-bef | before = [[Titus Flavius Postumius Titianus|T. Flavius Postumius Titianus]]|before2=Virius Nepotianus }}
{{s-ttl | title  = [[List of Roman consuls|Roman consul]] IV| years = 302 | regent1 = [[Galerius|Galerius Augustus]] }}
{{s-aft | after  = [[Diocletian|Diocletian Augustus]]|after2=[[Maximian|Maximian Augustus]] }}
{{s-bef | before = [[Diocletian|Diocletian Augustus]]|before2=[[Maximian|Maximian Augustus]] }}
{{s-ttl | title  = [[List of Roman consuls|Roman consul]] V| years = 305–306 | regent1 = [[Galerius|Galerius Augustus]] }}
{{s-aft | after  = [[Maximian|Maximian Augustus]]|after2=[[Constantine I|Constantine Augustus]]|after3=[[Severus II|Severus Augustus]]|after4=[[Maximinus Daza|Maximinus Augustus]]|after5=[[Galerius|Galerius Augustus]] }}
{{s-reg | leg }}
{{s-bef | before = [[King Cole|Coel]] }}
{{s-ttl | title  = [[List of legendary kings of Britain|King of Britain]] | years = 305–306 }}
{{s-aft | after  = [[Constantine I]] }}
{{s-end}}

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