1914 Beginning of the war . . On 6 August 1914 an
Anglo-French naval agreement was signed, giving France leadership of naval operations in the Mediterranean. The remaining
British Mediterranean forces – one
armoured cruiser, four
light cruisers, and 16
destroyers – were placed under the control of the
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 and , and the cruiser . Two French squadrons of
pre-dreadnought battleships, 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 off
Bar on 16 August in the
Battle of Antivari. However, Allied hopes of baiting the Austrian
capital ships into an action were not realized. 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 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
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
minefields 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 sank or were damaged.
The Goeben In July, , a 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, 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 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. In mid-December, the French submarine 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 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 armoured cruiser off
Paxos, but was unable to fire any torpedoes.
U-5 also torpedoed the French armoured 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
Viribus Unitis, , 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. on . The destroyer shelled the Italian airship
Città di Ferrara off Ancona. The semi-dreadnought and two torpedo boats bombarded
Potenza Picena, then returned to Pola. The
Radetzky-class semi-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 the armoured cruiser —with two torpedo boats—shelled
Rimini, damaging and derailing 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 boats dropped bombs on
Venice and
airship hangars at
Chiaravalle.
Allied raids 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 as a consequence. 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 —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 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, sank the Italian submarine and torpedo boat ; sank the Italian torpedo boat
PN 5 on June 26 off Venice;
U-4 torpedoed and sank the 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, 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
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 in Brindisi harbour by Italian-speaking Austro-Hungarian
saboteurs. 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
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 was rammed by the cruiser SMS
Helgoland, and finally sunk by gunfire from the destroyer . 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. 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 (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 , , and
Velebit attacked the
drifters 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
Casques 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
Gloucester 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-25s 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 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. 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. Although the attack was materially inconsequential, it boosted Italian morale in the wake of Italy's major defeat on the
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). 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.
The Premuda attack 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-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. 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. It is debated that faults in the design – relatively low
displacement and high
centre of gravity, together with the weight of twelve 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. 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, which had by that time come under Austro-Hungarian occupation, 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 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 In the final days of the war, Allied forces
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
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==