View source for Adriatic Campaign of World War I

{{Infobox military conflict
|conflict=Battle of the Adriatic
|image=Italien 1905.png
|image_size = 300px
|caption=The [[Adriatic Sea]] (upper right) during World War I, in an Austro-Hungarian map.
|partof=[[World War I]], [[Mediterranean naval engagements during World War I|Battle of the Mediterranean]]
|date=1914–1918
|place=[[Adriatic Sea]]
|result=Allied victory
|combatant1='''[[Allies of World War I|Allies]]:'''<br/>{{naval|Kingdom of Italy}}<br/>{{naval|United Kingdom}}<br/>{{naval|France}}<br/>{{naval|Australia|1913}}<br/>{{flag|United States Navy|1912}}
|combatant2='''[[Central Powers]]:'''<br/>{{naval|Austria-Hungary}}<br/>{{naval|German Empire}}
|commander1=
|commander2= 
|strength1=
|strength2=
|casualties1=
|casualties2=
|notes=
}}
{{Campaignbox Mediterranean Sea 1914-1918}}

The '''Adriatic Campaign of World War I''' was a naval campaign fought between the [[Central Powers]] and the [[Mediterranean]] squadrons of the [[Allies of World War I|Allies]], specifically the [[United Kingdom]], [[France]], the [[Kingdom of Italy (1861–1946)|Kingdom of Italy]], [[Australia]], and the [[United States]].

==Characteristics==
[[First World War]] naval action in the [[Adriatic Sea]] consisted mainly of Austro-Hungarian bombardments of Italy's eastern coast, and wider-ranging [[Empire of Germany|German]] and [[Austro-Hungarian Empire|Austro-Hungarian]] submarine forays into the Mediterranean.

Allied forces mainly limited themselves to blockading the Central Powers' navies in the Adriatic, which was successful in regards to surface units, but failed for the [[U-boats]], which found safe harbours and easy passage into and out of the area for the whole of the war. 

Considered a relatively secondary part of the naval warfare of World War I, it nonetheless tied down significant forces.

The Adriatic campaign was also important because for the first time two new weapons were used successfully in warfare, viz. the [[MAS (motorboat)|MAS torpedo boat]] of [[Luigi Rizzo]] that sank the battleship {{SMS|Szent István||2}} and the [[human torpedo]] of [[Raffaele Rossetti]] that sank the battleship {{SMS|Viribus Unitis||6}} in 1918.

==History==
===1914===
====Beginning of the war====
[[File:Austro-Hungarian Dreadnoughts At Pula.jpg|thumb|right|Austro-Hungarian dreadnoughts at [[Pula|Pola]].]]
[[File:Jean Bart (1911).jpg|right|thumb|The French [[battleship]] {{ship|French battleship|Jean Bart|1911|2}}.]]

On 6 August 1914 an [[wikt:Anglo-French|Anglo-French]] naval agreement was signed, giving France leadership of naval operations in the Mediterranean. The remaining [[Mediterranean Fleet (United Kingdom)|British Mediterranean forces]] – one [[armoured cruiser]], four [[light cruiser]]s, and 16 [[destroyer]]s – were placed under the control of the [[Mediterranean Fleet (France)|French Mediterranean Fleet]], and bases at both [[Gibraltar]] and [[Malta]] were opened to the French.

One day after the French declaration of war against Austria-Hungary on 11 August, a French fleet under Admiral [[Augustin Boué de Lapeyrère]] arrived at [[Malta]]. He had orders to sail with all available French and British ships, pass into the Adriatic Sea, and undertake whatever operations he thought best against Austrian ports. Lapeyrère decided to surprise Austrian vessels enforcing a blockade of [[Montenegro]]. The main Allied force comprised the French battleships {{ship|French battleship|Courbet|1911|2}} and {{ship|French battleship|Jean Bart|1911|2}}, and the cruiser {{ship|French cruiser|Jurien de la Gravière||2}}. Two French squadrons of [[pre-dreadnought battleship]]s, two squadrons of cruisers, and five destroyer squadrons were held back in support. The British support group comprised two armoured cruisers and three destroyer divisions. The Anglo-French force succeeded in cutting off and sinking the old Austro-Hungarian light cruiser {{SMS|Zenta||6}} off [[Bar, Montenegro|Bar]] on 16 August in the [[Battle of Antivari]]. However, Allied hopes of baiting the Austrian [[capital ship]]s into an action were not realized.

Throughout most of late August most of the action was simple bombardment of [[Serbia]]n and Montenegrin troops by Austrian ships. On 9 August, the pre-dreadnought {{SMS|Monarch||6}} shelled the French radio station at [[Budva]], while the destroyer {{SMS|Panther|1885|6}} shelled [[Mount Lovćen]]. On 17 August, ''Monarch'' shelled a Montenegrin radio station off Bar, then another station off [[Volovica Point]] on 19 August. Meanwhile, a French squadron shelled Austrian troops on [[Prevlaka]].

The French and Montenegrin forces attempted to cause havoc also at [[Kotor|Cattaro]] in September, October and November 1914, and the Austro-Hungarian navy was called in there also, resulting in a decisive defeat for the Allies.

Both the French and the Austrians spent much of this time laying extensive [[minefield]]s throughout the shallow waters of the Adriatic. Mostly this was done by destroyers, and at night. Several [[steamship]]s ran afoul of these mines and either sank or were damaged.

====The ''Goeben''====
{{main|Pursuit of Goeben and Breslau}}

In July, {{SMS|Goeben||6}}, a German [[battlecruiser]], sailed to [[Triest]] from [[Pula|Pola]]. She and the German cruiser {{SMS|Breslau||6}} had been anchored there since the beginning of the summer. On 1 August, ''Goeben'' and ''Breslau'' rendezvoused at [[Brindisi]], then headed for [[Messina]] to take on coal. They left for [[Constantinople]] on 6 August, shadowed by the British cruiser {{HMS|Gloucester|1909|6}}.

On 7 August, an Austro-Hungarian Fleet—consisting of six battleships, two cruisers, and 19 destroyers and torpedo boats—sortied from Pola to escort ''Goeben'' and ''Breslau'' through Austro-Hungarian territorial waters, returned to port following day without ever making contact. ''Goeben'' and ''Breslau'' briefly engaged HMS ''Gloucester'' and the chase was abandoned by the British. By 10 August, both German warships were safely in the [[Dardanelles]] and heading for [[Turkey]].

====Winter====
In November, the French submarine {{ship|French submarine|Cugnot||2}} managed to slip into the [[Bay of Kotor|Bocche di Cattaro]] as far as [[Topla Bay]] but was chased out by the Austrian destroyer {{SMS|Blitz|1882|6}}, and the torpedo boat ''Tb 57T''. In mid-December, the French submarine {{ship|French submarine|Curie|Q87|2}} raided the harbour barrage of Pola to wait for her chance to intrude. Two days later, on 20 December, during an attempt to sneak into the harbour she got entangled in an [[anti-submarine net]] and could not free herself. Forced to surface for fresh air, she was sunk by the Austrian destroyer {{SMS|Magnet||6}} and ''Tb 63T'', with three casualties. The Austrians raised the wreck between December 1914 and February 1915. It was then repaired and commissioned as {{SMU|U-14|Austria-Hungary|2}} in June 1915.

On 21 December, the submarine {{SMU|U-12|Austria-Hungary|2}} scored one torpedo hit on the French battleship ''Jean Bart'' off [[Sazan]] Island. The battleship had to withdraw to Malta for extensive repairs.

===1915===
In February, the French destroyer {{ship|French destroyer|Dague||2}}—while escorting the transport ''Whitehead'' to Bar—was sunk after hitting a mine. Also that month, the Austrian submarine ''U-12'' was unsuccessfully attacked off [[Cape Mendra]] by a French submarine. Austrian destroyer {{SMS|Csikós}} shelled Montenegrin positions at Bar with ''Tb 15'' and ''Tb 68F''.

In April, the Austrian {{SMU|U-5|Austria-Hungary|2}}—commanded by Lt. [[Georg Ritter von Trapp]]—chased the French armoured cruiser {{ship|French cruiser|Victor Hugo||2}} off [[Paxos (island)|Paxos]], but was unable to fire any torpedoes. ''U-5'' also torpedoed the French armoured cruiser {{ship|French cruiser|Léon Gambetta||2}} after a two-day chase off [[Santa Maria di Leuca]], causing 684 fatalities including Rear-Admiral Sénès. Only 137 French sailors survived. The Austrian {{SMU|U-4|Austria-Hungary|2}} torpedoed and damaged the British light cruiser {{HMS|Dublin|1912|6}}. Also, the Austrian destroyer {{SMS|Warasdiner||6}} shelled enemy positions at Bar.

====Bombardment of Ancona====
{{Main|Bombardment of Ancona}}
[[File:Ancona mappa.png|right|thumb|Italian province of [[Ancona]].]]

When [[Italy]] declared war on Austria-Hungary on 23 May, the Austrian fleet was quick to act, launching several attacks on the [[Marche]] region of Italy.<ref name="Dario Petković 2004">{{Cite book|first=Dario|last=Petković|title=Ratna mornarica austro-ugarske monarhije|publisher=Pula|year=2004|isbn=953-6250-80-2}}</ref> That day, the destroyer ''Dinara'' and ''[[Tb 53T]]'' bombarded the port of [[Ancona]]. The destroyer {{SMS|Lika}}—on reconnaissance duty between [[Palagruža]] and [[Cape Gargano]]—shelled the [[semaphore line|semaphore]] and [[radio station]] at [[Vieste]] and fired upon the Italian destroyer {{ship|Italian destroyer|Turbine|1901|2}}. On 24 May, the bulk of the Austrian fleet at Pola sailed for the Italian Adriatic coast. This included the dreadnoughts ''Viribus Unitis'', {{SMS|Tegetthoff|1912|2}}, {{SMS|Prinz Eugen|1912|2}} and eight semi and pre-dreadnoughts. The fleet bombarded several cities and other targets in and around the [[Province of Ancona]], especially damaging the port and town of Ancona itself.
[[File:Gun turret on SMS Tegetthoff.JPG|thumb|left|[[Gun turret]] on {{SMS|Tegetthoff|1912|6}}.]]

The destroyer {{SMS|Velebit}} shelled the Italian airship [[M.2 Città di Ferrara|''Città di Ferrara'']] off Ancona. The semi-dreadnought {{SMS|Radetzky|1909|6}} and two torpedo boats bombarded [[Potenza Picena]], then returned to Pola. The ''Radetzky''-class semi-dreadnought {{SMS|Zrínyi}}, with two torpedo boats bombarded [[Senigallia]], destroying a train and damaging a railway station and a bridge, then returned to Pola. The torpedo boat ''Tb 3'' was unsuccessfully bombed by an Italian airship. The light cruiser {{SMS|Admiral Spaun}} shelled the Italian signal station at [[Tremiti Islands|Cretaccio Island]], while the armoured cruiser {{SMS|Sankt Georg||6}}—with two torpedo boats—shelled [[Rimini]], damaging and derailing a freight train. The destroyer {{SMS|Streiter}} shelled the signal station near [[Torre di Mileto]]. The light cruiser {{SMS|Novara|1913|6}}, a destroyer and two torpedo boats entered [[Corsini Channel]] and shelled an Italian torpedo boat station, a semaphore station, and coastal artillery batteries.

The light cruiser {{SMS|Helgoland|1912|6}}—aided by four destroyers—sank the Italian destroyer ''Turbine'' in a pitched battle south of [[Pelagosa]]. The destroyer {{SMS|Tátra}} shelled the railway embankment near [[Manfredonia]] while the destroyer {{SMS|Csepel}} shelled the Manfredonia railway station.

Finally, Austro-Hungarian [[flying boat]]s dropped bombs on [[Venice]] and [[airship hangar]]s at [[Chiaravalle (AN)|Chiaravalle]].

====Allied raids====
{{Main|Raid on Porto Buso}}
Coincidentally with the Austro-Hungarian attack on Ancona, the Italian destroyer ''Zeffiro'' shelled and captured the Austro-Hungarian naval station and post at Porto Buso on the first hours of 24 May. Austro-Hungarian troops withdrew from the nearby town of [[Grado, Friuli Venezia Giulia|Grado]] as a consequence.<ref name=":2">{{Cite web |date=14 February 2010 |title=Prima Azione Della R. Marina |url=http://www.betasom.it/forum/index.php?/topic/32636-prima-azione-della-r-marina/ |access-date=2020-03-26 |website=Betasom – XI Gruppo Sommergibili Atlantici |language=en-US}}</ref>

On 5 June, four different Allied task forces attacked the Austrian coast. Four Italian armoured cruisers, escorted by four French destroyers, shelled [[Cavtat]]; the British cruiser ''Dublin''—escorted by five Italian destroyers—shelled [[Donzella]]; the Italian light cruiser {{ship|Italian cruiser|Quarto||2}}—escorted by four destroyers—bombarded [[Lastovo]]; the Italian light cruiser {{ship|Italian cruiser|Nino Bixio||2}}, two Italian and two French destroyers shelled the island of [[Vis (island)|Lissa]]. On 9 June, a mixed force of British, French and Italian destroyers shelled the Austro-Hungarian signal station at [[Cape Rondini]] in [[Albania]].

====The summer of 1915====
''Sankt Georg'' and a squadron of torpedo boats bombarded Rimini on 16 June, causing minor damage. Then on 17 June, the cruisers ''Novara'' and ''Admiral Spaun'' and their escorts attacked and sank the Italian steamer ''Maria Grazia'' off [[Giulianova]]. The next day, they shelled Rimini and [[Fano]], destroying the Italian signal station there.

The summer of 1915 was a successful time for Austrian submarines as well: on 10 June, {{SMU|U-11|Austria-Hungary|2}} sank the Italian submarine {{ship|Italian submarine|Medusa|1911|2}} and torpedo boat {{ship|Italian torpedo boat|Serpente||2}}; {{SMU|U-10|Austria-Hungary|2}} sank the Italian torpedo boat ''PN 5'' on June 26 off Venice; ''U-4'' torpedoed and sank the {{ship|Italian cruiser|Giuseppe Garibaldi|1899|2}} on 18 July; and ''U-5'' captured the Greek steamer ''Cefalonia'' off Durazzo on August 29. But this was not without losses. On 13 August, {{SMU|U-3|Austria-Hungary|2}} was sunk at Brindisi by the French destroyer [[Bisson-class destroyer|''Bisson'']]<!-- {{ship|French destroyer|Bisson||2}}-->, after having been severely damaged by the Italian auxiliary cruiser {{ship|Italian auxiliary cruiser|Città di Catania||2}} the day before.

The Austro-Hungarian naval air-arm also began regular bombing raids against [[Bari]] and Brindisi in June, slightly damaging the British protected cruiser {{HMS|Amethyst|1903|6}} in one such raid with machine gun fire. And the British [[Naval trawler|armed trawler]] ''Schiehallion'' was sunk by a mine. The {{ship|Italian cruiser|Amalfi||2}} was sunk off Venice by the German submarine {{SMU|UB-14||2}} on July 2. While the Italian scout cruiser {{ship|Italian cruiser|Marsala||2}} shelled [[Gravosa]] station on 18 July, the scout cruiser ''Quarto'' and three Italian destroyers attacked the Austrian installation at [[Guiparra]].

SMS ''Helgoland'', seven destroyers and four torpedo boats supported an Austrian landing at Pelagosa on 28 July. The landing was repulsed by the Italian garrison, that had arrived in the island on July 11. On August 17 the light cruisers "Helgoland", "Saida" and several destroyers bombarded the island again. The water reservoir was severely damaged and the next day the Italians began the evacuation. On 17 August, one of the cruisers was unsuccessfully torpedoed by an Italian submarine on return journey. The last act of the summer was the sinking on 26 September of the Italian battleship {{ship|Italian battleship|Benedetto Brin||2}} in Brindisi harbour by Italian-speaking Austro-Hungarian [[saboteur]]s. Over 450 were killed.

In late September, the Allies established the [[Otranto Barrage]], an attempt to blockade the entrance to the Adriatic Sea at the [[Strait of Otranto]].

====December====
[[File:Monge-Marius Bar-img 3154.jpg|thumb|The French submarine ''Monge'']]

In early December, the French submarine {{ship|French submarine|Fresnel|1908|2}} ran aground off the [[Bojana River]] estuary due to bad navigation, and was sunk by the Austrian destroyer {{SMS|Warasdiner||6}}. The cruiser ''Helgoland'' and three destroyers sortie against the Otranto Barrage from 5–22 December and performed reconnaissance off the Albanian coast and [[San Giovanni di Medua]]. They sank an Italian picket boat, three steamships loaded with ammunition and two armed schooners ''en route'' to Northern Albania.

The light cruiser SMS ''Helgoland'' and five Tatra-class destroyers left Cattaro and headed for Durazzo late on 28 December 1915. While on passage the French submarine {{ship|French submarine|Monge|1910|2}} was rammed by the cruiser SMS ''Helgoland'', and finally sunk by gunfire from the destroyer {{SMS|Balaton}}. Early the next day, the Austrians squadron opened fire on Durazzo targets, sinking some small ships. Then they ran into a minefield. The destroyer ''Lika'' was sunk and ''Triglav'' was damaged. She was taken in tow and the Austrian force sailed slowly to north.

An allied force had already sailed from Brindisi, with the aim to intercept them. It was composed of the British light cruisers HMS ''Dartmouth'' and ''Weymouth'', the Italian light cruisers RN ''Quarto'' and ''Nino Bixio'' and five French destroyers. In support of the retreating force, the Austrians despatched the armoured cruiser SMS ''Kaiser Karl VI'' and the light cruiser ''Novara'' from Cattaro. Early in the afternoon of 29 December, the forward Allied ships came into action with the retreating Austrian light squadron, which was still only halfway home. The ''Triglav'' was abandoned and scuttled and a long-range gunnery duel was fought throughout the afternoon. SMS ''Tatra'' was damaged but the Austrian light force was able to reach Cattaro safely.

===1916===
Austrian submarines sank or damaged a number of ships in 1916. ''U-11'' captured the Italian hospital ship ''King Albert'' on 18 January at San Giovanni di Medua. {{SMU|U-6|Austria-Hungary|2}} sank the French destroyer {{ship|French destroyer|Renaudin||2}} on 16 March at [[Durrës|Durazzo]]. On 8 June, ''U-5'' torpedoed and sank the Italian troop transport ''Principe Umberto'' at [[Linguetta]]. Later, ''U-5'' fought a French-Italian destroyer group to a stalemate on 2 August, and torpedoed the Italian Q-Ship ''Pantelleria'' south of [[Taranto]] on August 14.

On 15 September 1916, the two Austro-Hungarian seaplanes L.132 and L.135 forced the French submarine {{ship|French submarine|Foucault||2}} to surface by dropping bombs. L.135 finally sinks the sub while the 27 survivors were clinging to the two planes now floating, to be finally saved by the alarmed ''Tb 100M''. This was the first sinking of a submarine by airplanes in naval war history.

The very same day, the French submarine ''Ampére'' scored two torpedo hits on the Austro-Hungarian Hospital ship ''No I'' (the former Lloyd steamer ''Elektra'') off [[Cape Planka]] (Rt Ploča), causing two fatalities. The damaged hospital ship had to be beached in Borovica Bay for further repairs.

On the night of 22/23 December, the Austro-Hungarian destroyers {{SMS|Scharfschuetze||6}}, {{SMS|Reka||2}}, {{SMS|Dinara||2}} and ''Velebit'' attacked the [[Naval drifter|drifter]]s patrolling the Otranto barrage, which applied for help to the French destroyers {{ship|French destroyer|Casque|1910|2}}, {{ship|French destroyer|Protet||2}}, {{ship|French destroyer|Commandant Rivière||2}}, {{ship|French destroyer|Commandant Bory||2}}, {{ship|French destroyer|Dehorter||2}} and {{ship|French destroyer|Boutefeu||2}} which were escorting a convoy from Brindisi to Taranto. Because of communication problems, only ''Casque'' and ''Commandant Rivière'' attacked, but ''Casque''{{'}}s boiler rooms were hit immediately and she had to slow down to {{convert|23|kn|lk=in}}. For further assistance, the Italian destroyers {{ship|Italian destroyer|Giuseppe Cesare Abba||2}}, {{ship|Italian destroyer|Ippolito Nievo||2}} and {{ship|Italian destroyer|Rosolino Pilo||2}} left Brindisi shortly followed by the British cruiser ''Gloucester'' escorted by {{ship|Italian destroyer|Impavido|1913|2}} and {{ship|Italian destroyer|Irrequieto||2}}. The French and Italian groups met during darkness, ''Giuseppe Cesare Abba'' rammed ''Casque''; some moments later, ''Boutefeu'' rammed ''Giuseppe Cesare Abba''. While the damaged vessels had to be taken into tow, the Austrians escaped in the darkness.

The return from the Otranto battle—15 May 1917—brought the British cruiser {{HMS|Dartmouth|1910|6}} within the range of the {{SMU|UC-25||2}} which had already laid mines off Brindisi.

At 13:30, ''UC-25'' torpedoed ''Dartmouth'' approximately {{convert|36|mi|nmi km|lk=on|abbr=on}} off Brindisi, for some time the ship was considered to be lost, but was manned by a rescue crew later and finally towed into port. On hearing that ''Dartmouth'' had been torpedoed, ''Boutefeu'' went to assist, only to hit one of ''UC-25''{{'}}s mines.

===1917===
The Austro-Hungarian Navy had a major victory in May 1917 when it broke out of the allied naval blockade of the Adriatic Sea during the [[Battle of the Strait of Otranto (1917)]].  However after this, large scale operations were limited. By August 1917, Lt. Von Trapp and ''U-14'' had sunk more than {{convert|24000|LT|t|lk=on|abbr=on}} of enemy shipping, including the Italian steamer ''Milazzo'' ({{convert|11480|LT|t|abbr=on}}). ''U-4'' torpedoed the French steamer ''Italia'' near Taranto on 30 May, and on 16 November {{SMU|U-43|Austria-Hungary|2}} severely damaged the Italian steamer ''Oriona'' between Brindisi and [[Vlorë|Valona]]. On the night of 9–10 December, while SMS ''Wien'' and ''Budapest'' were at anchor in Trieste, two Italian MAS (motor torpedo boats) managed to penetrate the harbour defences undetected and fired several torpedoes at the two ships. ''Wien'' was struck by two torpedoes and sank in less than five minutes with the loss of 46 of her crew.

===1918===
During the night of 10–11 February 1918, three Italian MAS boats raided the harbor at [[Bakar, Croatia|Bakar]]. Although the attack was materially inconsequential, it boosted Italian morale in the wake of Italy's major defeat on the [[Italian front (World War I)|Italian front]] in the [[Battle of Caporetto]] in October–November 1917 and was widely celebrated in Italy, where it became known as the ''Beffa di Buccari'' ([[Bakar mockery]]).<ref>Halpern, p 172.</ref><ref>{{Cite web|title=MAS 96 - Gruppo di Cultura Navale|url=http://www.culturanavale.it/documentazione.php?id=258|access-date=2021-07-13|website=www.culturanavale.it|lang=it}}</ref>

On 13 February, the submarine {{ship|French submarine|Bernouilli|Q83|2}} (Audry) was lost with all hands after hitting a mine off the Bocche di Cattaro.

On 22/23 April, the Austro-Hungarian {{sclass|Tátra|destroyer|2}}s {{SMS|Triglav|1917|6}}, {{SMS|Uzsok}}, {{SMS|Dukla}}, SMS ''Lika'' and SMS ''Csepel'' encountered the British destroyers {{HMS|Jackal|1911|6}} and {{HMS|Hornet|1911|2}}, the Australian {{HMAS|Torrens|D67|6}} and the French {{ship|French destroyer|Cimeterre||2}}. HMS ''Hornet'' was badly damaged in the ensuing fight but the alarm went up and the Austrians turned for home, pursued by ''Jackal'', who had lost her mainmast.

====The Premuda attack====
[[File:Affondamento Santo Stefano.jpg|thumb|right|The last moments of SMS ''Szent István'', hit by a torpedo of the Italian MAS of [[Luigi Rizzo]]]]
At 03:30 on the morning of 10 June 1918, the battleship ''Szent István''—in the company of SMS ''Tegetthoff'' and seven other ships ''en route'' to attack the Otranto Barrage – was seen by chance and then hit by two torpedoes launched from the Italian [[MAS (ships)|MAS]]-15 [[Motor Torpedo Boat]] under Corvette Captain Luigi Rizzo near [[Premuda]] island, near [[Zadar|Zara]]. Many of the 1,087 crew were asleep, getting rested for the battle expected in a few hours. Immediate chaos soon changed into frantic efforts to save the vessel which was rapidly shipping water. SMS ''Tegetthoff'' was hit by another torpedo from a second MAS, but it did not explode.

Then ''Tegetthoff''—which had at first sped away from the vicinity of the torpedo attack—returned and took ''Szent István'' in tow, in an attempt to reach the massive dry dock at Pula. However, the pumps were unequal to the task before them due to loss of steam pressure and the ship continued to slowly list, sinking at 06:12, almost 3 hours after being hit.<ref name="Dario Petković 2004"/>

It is debated that faults in the {{sclass|Tegetthoff|battleship|0}} design – relatively low [[Displacement (fluid)|displacement]] and high [[centre of gravity]], together with the weight of twelve {{convert|305|mm|in|0|abbr=on}} main artillery – did not assist matters. However, most other battleships in The Great War which were either torpedoed or mined sank far more rapidly. There were, however, only 89 dead, partly attributed to the fact that all sailors with the K.u.K. had to learn to swim before entering active service. The attack on the Otranto Barrage was cancelled as a consequence of this attack.<ref name="Dario Petković 2004"/>

On 20 September, the French submarine {{ship|French submarine|Circé|Q47|2}} was torpedoed {{convert|7|nmi|abbr=on}} north west of Cape Rodoni by the Austro-Hungarian submarine {{SMU|U-47|Austria-Hungary|2}} and lost with all hands.

====Second Battle of Durazzo====
On 2 October, an allied fleet composed of Italian, British, Australian and American warships attacked the port of Durazzo, which had by that time come under Austro-Hungarian occupation, during the [[Battle of Durazzo (1918)|Second Battle of Durazzo]]. The fleet consisted of over 55 vessels along with MAS boats and supporting aircraft. Allied forces destroyed Austro-Hungarian shore batteries and defeated a small squadron of patrol craft while sustaining comparatively light damage. Durazzo was left in flames, several building, bridges and railroad targets were bombarded which forced the evacuation of the city. A week or so after the battle an allied army occupied the city without resistance.

====Sinking of ''Viribus Unitis''====
On 1 November, the ex-Austro-Hungarian [[dreadnought]] [[flagship]] ''Viribus Unitis'' was sunk – along with the merchant-ship ''Wien''— both at anchor at Pula by  [[limpet mine]] attached by the crew of an Italian ''[[mignatta]]''. The ''mignatta'' was the precursor of the [[human torpedo]] and was invented by Major of naval engineers Raffaele Rossetti.

The whole Austro-Hungarian Navy was at the time being transferred to the new [[State of Slovenes, Croats and Serbs]], but the Italian attackers had not been informed.

====Allied occupation of the eastern Adriatic====
{{main|Allied occupation of the eastern Adriatic}}
In the final days of the war, Allied forces [[Allied occupation of the eastern Adriatic|occupied the eastern Adriatic]]. The occupation generally encompassed [[Julian March]], [[Dalmatia]], and the coastal areas of the [[Kingdom of Montenegro]]. The occupied area was partitioned in four zones: British, French, American, and Italian. The latter largely corresponded to the territorial award under the [[Treaty of London (1915)|1915 Treaty of London]]. The occupation was a part of efforts to address the [[Adriatic question]] of determination of borders of Italy in the Adriatic. Certain elements of the occupation were significant in resolution of the [[Fiume question]] (concerning political future of the city of [[Rijeka]]/Fiume) and the [[Montenegrin question]] (concerning preservation of independence of that kingdom). The occupation concluded in 1921.

==Austro-Hungarian submarine results==
{{Main|Mediterranean U-boat Campaign (World War I)}}

Many Austro-Hungarian and German U-boats operated out of the Adriatic for the whole of the war. Due to lack of cooperation of the Allies in the Mediterranean control zones, and the late institution of the convoy system, U-boats experienced substantial success throughout the first war years.<ref name="WILL">{{Cite book|title=First World War|last=Willmott|first=H. P.|publisher=[[Dorling Kindersley]]|year=2003|pages=186–187}}</ref>

[[Austro-Hungarian Navy|''K.u.K. Kriegsmarine'']] submarines sunk 117 ships during World War I, with the total of {{convert|220121|LT|t}}. The most well-known casualties were:<ref name="Dario Petković 2004, Page 84"/>
* {{ship|French armoured cruiser|Léon Gambetta||2}}
* {{ship|Italian cruiser|Giuseppe Garibaldi|1899|2}}
* {{ship|Italian submarine|Nereide|1913|2}}
* {{ship|French destroyer|Renaudin||2}}
* {{ship|French destroyer|Fourche||2}}
* {{ship|Italian destroyer|Impetuoso|1913|2}}
* {{ship|Italian destroyer|Nembo|1901|2}}
* {{HMS|Phoenix|1911|6}}
* {{ship|French submarine|Circé|Q47|2}}

Also, the ''K.u.K. Kriegsmarine'' submarines damaged the following ships:<ref name="Dario Petković 2004, Page 84"/>
* {{ship|French battleship|Jean Bart|1911|2}}
* {{HMS|Dublin|1912|6}}
* {{ship|Japanese destroyer|Sakaki|1915|2}}
* {{HMS|Weymouth|1910|6}}

{|class="wikitable" align="left" style="margin:0 1em 0.5em 0;"
|+'''Tonnes sunk by K.u.K. Kriegsmarine submarines'''
|-
!Year
!1914
!1915
!1916
!1917
!1918
|-
!Tonnage
|13
|22.568
|25.716
|112.716
|58.902 
|-
! colspan="6" | <small>Source:</small><ref name="Dario Petković 2004, Page 84">{{Cite book|first= Dario|last=Petković|title=Ratna mornarica austro-ugarske monarhije|publisher= Pula|year=2004|page=84|isbn=953-6250-80-2}}</ref>
|}
{{Clear}}

==References==
===Citations===
{{Reflist}}
===Bibliography===
* {{cite book |last=Halpern |first=Paul |title=A Naval History of World War I |year=1995 |publisher=Routledge |location=New York |isbn=978-1-85728-498-0}}

==External links==
* [https://web.archive.org/web/20070927222605/http://www.naval-history.net/WW1CampaignsSerbia.htm Serbia, Balkans & Macedonia 1914-18]
* [http://worldatwar.net/chandelle/v1/v1n2/adriatic.html Combined Operations in the Adriatic, 1915-18]

{{Authority control}}

{{DEFAULTSORT:Adriatic Campaign Of World War I}}
[[Category:Military operations of World War I involving Austria-Hungary]]
[[Category:Mediterranean naval operations of World War I]]
[[Category:Campaigns and theatres of World War I]]
[[Category:Military history of the Mediterranean]]