Adriatic Campaign of World War II

The Adriatic Campaign of World War II was a minor naval campaign fought during World War II between the Greek, Yugoslavian and Italian navies, the Kriegsmarine, and the Mediterranean squadrons of the United Kingdom, France, and the Yugoslav Partisan naval forces. Considered a somewhat insignificant part of the naval warfare in World War II, it nonetheless saw interesting developments, given the specificity of the Dalmatian coastline.

Prelude — Italian invasion of Albania
On 7 April 1939, Mussolini's troops occupied Albania, overthrew Zog, and annexed the country to the Italian Empire. Naval operations in the Adriatic consisted mostly of transport organisation through the ports of Taranto.

Greco-Italian War
The Greco-Italian War lasted from 28 October 1940 to 30 April 1941 and was part of World War II. Italian forces invaded Greece and made limited gains. At the outbreak of hostilities, the Royal Hellenic Navy was composed of the old cruiser GREEK CRUISER Georgios Averof, 10 destroyers (four old Theria class, four relatively modern Dardo class and two new Greyhound class), several torpedo boats and six old submarines. Faced with the formidable Regia Marina, its role was primarily limited to patrol and convoy escort duties in the Aegean Sea. This was essential both for the completion of the Army's mobilization, but also for the overall resupply of the country, the convoy routes being threatened by Italian aircraft and submarines operating from the Dodecanese Islands.

Nevertheless, the Greek ships also carried out limited offensive operations against Italian shipping in the Strait of Otranto. The destroyers carried out three bold but fruitless night-time raids (14–15 November 1940, 15–16 December 1940 and 4–5 January 1941). The main successes came from the submarines, which managed to sink some Italian transports. On the Italian side, although the Regia Marina suffered severe losses in capital ships from the British Royal Navy during the Taranto raid, Italian cruisers and destroyers continued to operate covering the convoys between Italy and Albania. Also, on 28 November, an Italian squadron bombarded Corfu, while on 18 December and 4 March, Italian task forces shelled Greek coastal positions in Albania.

Invasion of Yugoslavia
The Invasion of Yugoslavia (also known as Operation 25) began on 6 April 1941 and ended with the unconditional surrender of the Royal Yugoslav Army on 17 April. The invading Axis powers (Nazi Germany, Fascist Italy and Hungary) occupied and dismembered the Kingdom of Yugoslavia.

When Germany and Italy attacked Yugoslavia on 6 April 1941, the Yugoslav Royal Navy had available three destroyers, two submarines and 10 MTBs as the most effective units of the fleet. One other destroyer, the Ljubljana was in dry-dock at the time of the invasion and she and her anti-aircraft guns were used in defence of the fleet base at Kotor. The remainder of the fleet was useful only for coastal defence and local escort and patrol work.

Kotor (Cattaro) was close to the Albanian border and the Italo-Greek front there, but Zara (Zadar), an Italian enclave, was to the north-west of the coast and to prevent a bridgehead being established, the destroyer Beograd, four of the old torpedo boats and six MTBs were despatched to Šibenik, 41 ft80 km to the south of Zara, in preparation for an attack. The attack was to be co-ordinated with the 12th "Jadranska" Infantry Division and two Odred (combined regiments) of the Royal Yugoslav Army attacking from the Benkovac area, supported by air attacks by the 81st Bomber Group of the Royal Yugoslav Air Force.

The Yugoslav forces launched their attack on 9 April, but by 13 April the Italian forces -under the orders of General Vittorio Ambrosio- had counter-attacked and were in Benkovac by 14 April. The naval prong to this attack faltered when Beograd was damaged by near misses from Italian aircraft off Šibenik when her starboard engine was put out of action, after which she limped to Kotor, escorted by the remainder of the force, for repair.

The maritime patrol float-planes of the Royal Yugoslav Air Force flew reconnaissance and attack missions during the campaign, as well as providing air cover for mine-laying operations off Zara. Some of their successes included an Italian tanker being damaged by a near miss off the Italian coast near Bari, attacks on the Albanian port of Durrës, as well as strikes against Italian re-supply convoys to Albania. On 9 April, one Dornier Do 22K floatplane notably took on an Italian convoy of 12 steamers with an escort of eight destroyers crossing the Adriatic during the day, attacking single-handed in the face of intense AA fire.

Italian occupation and Yugoslav resistance


After the invasion, Italy controlled the entire eastern Adriatic coast through the annexation of much of Dalmatia, the Italian occupation zone of the Independent State of Croatia, and the Italian puppet regimes of the Kingdom of Montenegro (1941–1944) and the Albanian Kingdom (1939–1943).

Naval forces of the Yugoslav Partisans were formed as early as 19 September 1942, when Partisans in Dalmatia formed their first naval unit made of fishing boats, which gradually evolved into a force able to engage the Italian Navy and Kriegsmarine and conduct complex amphibious operations. This event is considered to be the foundation of the Yugoslav Navy. At its peak during World War II, the Yugoslav Partisans' Navy commanded nine or 10 armed ships, 30 patrol boats, close to 200 support ships, six coastal batteries, and several Partisan detachments on the islands, around 3,000 men.

After the Italian capitulation of 8 September 1943, following the Allied invasion of Italy, the Partisans took most of the coast and all of the islands. On 26 October, the Yugoslav Partisans' Navy was organized first into four, and later into six Maritime Costal Sectors (Pomorsko Obalni Sektor, POS). The task of the naval forces was to secure supremacy at sea, organize defense of coast and islands, and attack enemy sea traffic and forces on the islands and along the coasts.

German occupation
As a first move (Operation Wolkenbruch) the Germans rushed to occupy the northern Adriatic ports of Trieste, Fiume and Pula, and established the Operational Zone Adriatic Coast OZAK, with its headquarters in Trieste, on 10 September. It comprised the provinces of Udine, Gorizia, Trieste, Pula (Pola), Rijeka (Fiume) and Ljubljana (Lubiana). Since an Allied landing in the area was anticipated, OZAK also hosted a substantial German military contingent, the Befehlshaber Operationszone Adriatisches Küstenland commanded by General der Gebirgstruppe Ludwig Kübler. On 28 September 1944, these units were redesignated XCVII Armeekorps. Soon also German marine units were formed. Royal Navy engagement was also on the rise.

German Navy in the Adriatic
Vize-Admiral Joachim Lietzmann was Commanding Admiral Adriatic (Kommandierender Admiral Adria). Initially, the area of operation ranged from Fiume to Valona, and the area of the Western coast was under the jurisdiction of the German navy for Italy (Deutsches Marinekommando Italien). The line of demarcation between the two naval commands and corresponded between the Armed Group F (Balkans) and the Armed Group E (Italy) as a border between the Italian Social Republic (RSI) and the Independent State of Croatia (NDH). Soon on Lietzmann insistence on the area of operation was extended to include the whole of Istria to the mouth of the Tagliamento, and in correspondence to the boundary line between the Italian Social Republic and the area of the Operational Zone Adriatic Coast(OZAK).

One of the first operations was Operation Herbstgewitter. This consisted of landing German troops on the islands of Krk, Cres and Lošinj in November 1943. The Germans used some old ships such as the cruiser SMS Niobe and the auxiliary cruiser ITALIAN SHIP Ramb III. During the action, the islands were cleared of partisan forces and Niobe with two S-boats managed to capture a British military mission on the island of Lošinj.

Gradually the German navy was built up, mostly with former Italian ships found in an advanced phase of construction in the yards of Fiume and Trieste. The strongest naval unit was the 11th Sicherungsflotille. Formed in May 1943 in Triest as the '11. Küstenschutzflottille, in December 1943 it was designated 11. Sicherungsflottille'. It was employed in protecting marine communications in the Adriatic, mostly from partisan naval attacks. On 1 March 1944, the Flotilla was extended and re-designated the '11. Sicherungsdivision'.

Occupation of Dalmatia
Until the end of 1943, the German forces were advancing into Dalmatia after capitulation of Italy.

In the summer of 1944, the Allies undertook a major evacuation of civilian population from Dalmatia fleeing the German occupation, and moved them to the El Shatt refugee camp in Egypt.

Vis island
By 1944, only Vis island remained unoccupied and divisions task become its defense against later cancelled German invasion (Operation FREISCHÜTZ). The island was about 14 mi long and 8 mi wide, with a mainly hilly perimeter, with a plain in the centre covered with vines, part of which has been removed to make way for an airstrip about 750 yd long, from which four Spitfires of the Balkan Air Force were operating. At the west end of the island was the Port of Komiža, while at the other end was the Port of Vis, these were connected by the only good road running across the plain.Vis was organized as a great stronghold, held until the end of World War II.

In 1944, Tito's headquarters moved there and British forces with over 1,000 troops was also included in the defence of Vis. The British forces, already on the island, were called Land Forces Adriatic, and were under the command of Brigadier George Daly, and consisted of the No. 40 (Royal Marine) Commando and No. 43 (Royal Marine) Commando of the 2nd Special Service Brigade, the Highland Light Infantry (part of the 51st Highland Infantry Division) and other support troops. Operating from the two ports were several Royal Navy craft, Marshal Tito's forces numbered about 2,000. Vis was functioning as the political and military center of the liberated territories until the liberation of Belgrade in late 1944.

A remarkable figure was the Canadian captain Thomas G. Fuller, son of the Canadian Chief Dominion Architect Thomas William Fuller, who in 1944 took command of the 61st MGB flotilla. Operating from the island of Vis he supplied the partisans by pirating German supply ships. He managed to sink or capture 13 German supply boats, was involved in 105 fire fights and another 30 operations where there was no gunfire. Characteristically for the Yugoslav operations theatre, Fuller attributed a good part of his success to the blood-curling threats uttered by the Yugoslav partisan who manned the MGB's loud hailer: a 400 ton schooner was captured with its whole cargo and whose crew gave up without a struggle because of the explanation of what would be done to them personally, with knives, if they disobeyed.

Liberation of Dalmatia
British naval forces in the Middle East operating in the Adriatic Sea were under the command of the Flag Officer Taranto and Adriatic & Liaison with the Italians (F.O.T.A.L.I). All the naval forces were controlled from Taranto and operated in close coordination with the Coastal attack operations conducted by the BAF. The Yugoslavs used the units in the British navy to transport materials and men, but especially to make landings on the islands of Dalmatia to liberate them from German occupation.

During the Vis period, Partisans carried out several seaborne landings on Dalmatian islands with help of Royal Navy and Commandos:
 * Korčula
 * Šolta - Operation DETAINED
 * Hvar - Operation ENDOWMENT
 * Mljet - Operation FARRIER
 * Brač - Operation FLOUNCED

The French Navy was involved as well in the first half of 1944, with the 10th Division of Light Cruisers made up of three Fantansque-class destroyers (Le Fantasque, Le Terrible, Le Malin) making high speed sweeps in the Adriatic, destroying German convoys.

In the second half of 1944 the Royal Navy sent a destroyer flotilla in the Adriatic. The biggest engagement happened on 1 November, when two Hunt-class destroyers HMS Avon Vale (L06) and HMS Wheatland were patrolling the coastal shipping routes south of Lussino in the Adriatic. That evening, two enemy corvettes were sighted; UJ-202 and UJ-208. The two destroyers opened fire at a range of 4000 yd. In less than 10 minutes, the enemy ships were reduced to mere scrap, the two British ships were circling the enemy and pouring out a devastating fire of pom-pom and small calibre gunfire. When the first corvette was sunk Avon Vale closed to rescue the Germans while Wheatland continued to shoot up the second corvette which eventually blew up. Ten minutes later, the British came under fire from the German Torpedoboot Ausland destroyer TA-20 (ex-Italian destroyer Audace) which suddenly appeared on the scene. When the two British ships directed their fire at her and the enemy destroyer was sunk. But while the Adriatic campaign continued to the end of the war, the Hunts did not again engage large German warships, although the German Navy was constantly launching and commissioning light destroyer types from the yards of Trieste and Fiume. Moreover, on 14 December, HMS Aldenham (L22) struck a mine around the island of Škrda and it was the last British destroyer lost in World War II.

To prevent entrance to the North Adriatic in the last two years of World War II, Germany spread thousands of mines and blocked all ports and canals. Many underwater mine fields were situated in the open sea. Mine sweeping was executed by British ships equipped with special mine-sweeping technology. On 5 May 1945, the Shakespeare-class trawler HMS Coriolanus hit a mine while it was sweeping the sea in front of Novigrad.

Planned allied landings
The Allies, first under French initiative of the general Maxime Weygand planned landings in the Thessaloniki area. Although discarded by the British, later the landing option became most advocated by Winston Churchill. The so-called Ljubljana gap strategy proved ultimately to be little more than a bluff owing to American refusal and skepticism upon the whole operation. nevertheless, the British command planned several landing operations in Dalmatia and Istria codenamed ARMPIT and a more ambitious plan GELIGNITE. Facing American opposition the British made last attempts were marked by sending an air force called FAIRFAX in Zadar area, and an artillery attachment called FLOYD FORCE also in Dalmatia, but due to Yugoslav obstruction such attempts ceased. Nevertheless, the bluff worked since Hitler eventually awaited an allied landing in the northern Adriatic, and diverted important resources in the area. Instead of landings the allied agreed to provide Tito land units with aerial and logistical support by setting up the Balkan Air Force.

The biggest British-led combined operation in the eastern Adriatic codenamed Operation Antagonise in December 1944 was intended to capture the island of Lošinj, where the Germans kept E-boats and (possibly) midget submarines. It was only partially executed since the partisan Navy Commander in Chief, Josip Černi, refused to give his troops for the landing operation. Instead, a group of destroyers and MTBs shelled the German gun positions and 36 South African Air Force Bristol Beaufighters attacked the naval base installations with RP-3 3 in Rocket Projectiles As the attacks proved ineffective in stopping German activities they were repeated also in the first months of 1945.

Final naval operations
By the end of October 1944, the Germans still had five destroyers (TA20, TA40, TA41, TA44, and TA 45) three corvettes (UJ205, UJ206, and TA48). On 1 January 1945, there were four German destroyers operative in the northern Adriatic (TA40, TA41, TA44, and TA 45) three U-Boot Jäger corvettes (UJ205, UJ206, and TA48). even as late as 1 April TA43, TA 45 and UJ206 were in commission and available to fight. Allied aircraft sank four in port (at Fiume and Trieste) in March and April, British MTB torpedoed TA 45 in April.

The very last operations of the German navy involved the evacuation of troops and personnel from Istria and Trieste before the advancing Yugoslavs that took place in May 1945. An estimated enemy force of 4,000 was landing from 26 ships of all types at the mouth of the Tagliamento River at Lignano Sabbiadoro. The area is a huge sand spit running out into a big lagoon, and at its southern end the Tagliamento River enters the sea. The Germans had evacuated Trieste to escape the Yugoslav Army. The Germans were protected by naval craft holding off three British MTBs, which could not get in close enough to use their guns effectively. There were about 6,000 of them and their equipment included E-boats, LSTs, a small hospital ship, all types of transport, and a variety of weapons. The 21st Battalion of the New Zealand 2nd Division was outnumbered by 20 to one, but at the end the Germans surrendered on 4 May 1945. Others had already surrendered to the British troops on German ships which arrived from Istria to Ancona on 2 May. British sources wrote there were about 30 boats, but no exact record is mentioned.