Adriatic Campaign of World War I The Adriatic Campaign of World War I was a naval campaign fought during World War I between the Central Powers , and the Mediterranean squadrons of Great Britain , France , the Kingdom of Italy , Australia and the United States . Characteristics . It consisted mainly of Austro - Hungarian coastal bombardments of Italy ′ s Adriatic coast , and wider - ranging German – Hungarian submarine warfare into the Mediterranean . Allied forces mainly limited themselves to blockading the German – Hungarian 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 important even because for the first time two new weapons were used successfully in warfare , viz . the human torpedo of Raffaele Rossetti and the MAS torpedo boat of Luigi Rizzo . These small navy vessels sank two Austrian battleships in 1918 , and . History . 1914 . Beginning of the war . On 6 August 1914 , an Anglo - French naval agreement was signed , giving France the leadership of naval operations in the Mediterranean . The remaining British Mediterranean forces , one armored cruiser , four light cruiser s , and 16 destroyer s were placed under the control of the French Mediterranean Fleet and both Gibraltar and Malta would be open as bases to the French . One day after the French declaration of war against Austria - Hungary on 11 August , the French fleet — under Admiral Augustin Boué de Lapeyrère — entered Malta . He had orders to sail with all available French and British ships , pass into the Adriatic Sea and undertake whatever operation he thought best against an Austrian port . Lapeyrère decided to surprise the Austrian vessels enforcing a blockade of Montenegro . The main Allied force comprised the French battleships , , and the cruiser . Two French squadrons of pre - dreadnought s , two squadrons of cruisers , and five destroyer squadrons were held back in support . The British support group comprised two armored cruisers and three destroyer divisions . The Anglo - French force succeeded in cutting off and sinking the Austro - Hungarian light cruiser off Bar on 16 August . Throughout most of late August most of the action was simple bombardment of Serbian and Montenegrin troops by Austrian ships . On 9 August , the pre - dreadnought shelled the French radio station at Budva , while the destroyer shelled Mount Lovcen . 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 . 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 steamships ran afoul of these mines and either sunk or were damaged . The " Goeben " . In July , the German battlecruiser sailed to Triest from Pola . She and the German cruiser 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 . On 7 August , the 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 managed to slip into the Bocche di Cattaro as far as Topla Bay but was chased out by the Austrian destroyer , and the torpedo boat " Tb 57T " . Later that month , the French submarine raided the harbor barrage of Pola to wait for her chance to intrude . Two days later , on 20 December , during an attempt to sneak into the harbor 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 and " Tb 63T " , with three casualties . The Austrians raised the wreck between December 1914 and February 1915 . It was then repaired and commissioned as in June 1915 . On 21 December , the submarine 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 — 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 shelled Montenegrin positions at Bar with " Tb 15 " and " Tb 68F " . In April , the Austrian — commanded by Lt . Georg Ritter von Trapp — chased the French armored cruiser off Paxos , but was unable to fire any torpedoes . " U - 5 " also torpedoed the French armored cruiser after a two - day chase off Santa Maria di Leuca , causing 684 fatalities including Rear - Admiral Sénès . Only 137 French sailors survived . The Austrian torpedoed and damaged the British light cruiser . Also , the Austrian destroyer shelled enemy positions at Bar . Bombardment 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 . That day , the destroyer " Dinara " and " Tb 53T " bombarded the port of Ancona . The destroyer — on reconnaissance duty between Palagruža and Cape Gargano — shelled the semaphore and radio station at Vieste and fired upon the Italian destroyer . On 24 May , the bulk of the Austrian fleet at Pola sailed for the Italian Adriatic coast . This included the dreadnoughts , , and eight pre - dreadnoughts . The fleet bombarded several cities and other targets in and around the Province of Ancona , especially damaging the port town of Ancona itself . The destroyer shelled the Italian airship " Città di Ferrara " off Ancona . The pre - dreadnought and two torpedo boats bombarded Potenza Picena , then returned to Pola . The " Radetzky " - class pre - dreadnought , 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 shelled the Italian signal station at Cretaccio Island , while — with two torpedo boats — shelled Rimini , damaging a freight train . The destroyer shelled the signal station near Torre di Mileto . The light cruiser , 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 — aided by four destroyers — sank the Italian destroyer " Turbine " in a pitched battle south of Pelagosa . The destroyer shelled the railway embankment near Manfredonia while the destroyer shelled the Manfredonia railway station . Finally , Austro - Hungarian flying boat s dropped bombs on Venice and airship hangar s at Chiaravalle . Allied raids . In response , 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 — escorted by five Italian destroyers — shelled Donzella ; the Italian light cruiser — escorted by four destroyers — bombarded Lastovo ; the Italian light cruiser , two Italian and two French destroyers shelled the island of 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 . The armored cruiser and a squadron of torpedo boats bombard Rimini on 16 June , causing minor damage . Then on 17 June , the cruisers , 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 , sank the Italian submarine and torpedo boat ; sank the Italian torpedo boat " PN 5 " on June 26 off Venice ; torpedoed and sank the on 18 July ; and captured the Greek steamer " Cefalonia " off Durazzo on August 29 . But this was not without losses . On 13 August , was sunk at Brindisi by the French destroyer " Bisson " , after having been severely damaged by the Italian auxiliary cruiser 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 in one such raid with machine gun fire . And the British armed trawler " Schiehallion " was sunk by a mine . The was sunk off Venice by the German submarine on July 2 . While the Italian scout cruiser shelled Gravosa station on 18 July , the scout cruiser and three Italian destroyers attacked the Austrian installation at Guiparra . SMS " Helgoland " , seven destroyers and four torpedo boats supported the Austrian landings at Pelagosa on 28 July , but within two weeks the battalion of troops are taken off . On 17 August , the cruiser was unsuccessfully torpedoed by an Italian submarine on return journey . The town ' s freshwater cistern was damaged during the bombardment and the Italian troop evacuation took place the following day . The last act of the summer was the sinking on 26 September of the Italian battleship in Brindisi Harbor 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 . In early December , the French submarine ran aground off the Bojana River estuary due to bad navigation , and was sunk by the Austrian destroyer . The cruiser SMS " 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 . On 30 December , the French submarine was rammed by the cruiser SMS " Helgoland " , and finally sunk by gunfire from the destroyer . 1916 . Austrian submarines sank or damaged a number of ships in 1916 . captured the Italian hospital ship " King Albert " on 18 January at San Giovanni di Medua . sank the French destroyer on 16 March at 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 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 ( Rat Ploca ) , 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 , , and attacked the drifter s patrolling the Otranto barrage , which applied for help to the French destroyers , , , , and 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 . For further assistance , the Italian destroyers , and left Brindisi shortly followed by the British cruiser escorted by and . 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 within the range of the which had already laid mines off Brindisi . At 13 : 30 , " UC - 25 " torpedoed " Dartmouth " approximately 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 . By August 1917 , Lt . Von Trapp and had sunk more than of enemy shipping , including the Italian steamer " Milazzo " ( ) . " U - 4 " torpedoed the French steamer " Italia " near Taranto on 30 May , and on 16 November severely damaged the Italian steamer " Oriona " between Brindisi and Valona . The Premuda attack . At 03 : 30 on the morning of 10 June 1918 , the battleship — in the company of SMS " Tegetthoff " and seven other ships " en route " to attack the Otranto Barrage — was hit by two torpedoes launched from the Italian MAS - 15 Motor Torpedo Boat under Corvette Captain Luigi Rizzo near Premuda island , near 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 . Even " Tegetthoff " was hit by another torpedo from a second MAS , but it did not exploded . 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 Pola . However , the pumps were unequal to the task before them and the ship continued to slowly list , sinking at 06 : 12 . It is said she sank easily due to faults in the design : relatively low displacement and high centre of gravity , together with the tremendous weight of twelve main artillery . 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 . 1918 . On 13 February , the submarine ( Audry ) was lost with all hands after hitting a mine off the Bocche di Cattaro . On 22 / 23 April , the Austro - Hungarian s , , , SMS " Lika " and SMS " Csepel " encountered the British destroyers and , the Australian and the French . 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 . On 20 September , the French submarine was torpedoed north west of Cape Rodoni by the Austro - Hungarian submarine 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 , Albania during the 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 the " Viribus Unitis " . On 1 November , the ex - Austro - Hungarian dreadnought flagship was sunk — along with the merchant ship " Wien " — at anchor at Pula by limpet mine attached by the crew of an Italian " mignatta " ( human torpedo ) . The " mignatta " was the precursor of the human torpedo and was invented by Major of naval engineers Raffaele Rossetti . The whole Austrian Navy was just being transferred to the new state after the dissolution of Austria Hungary . Austro - Hungarian submarines results . 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 . " K . u . K . Kriegsmarine " submarines sunk 117 ships during World War I , with the total of . The most well - known casualties were : Also , the " K . u . K . Kriegsmarine " submarines damaged the following ships :