The 'Campaign for the Dodecanese Islands' was an undertaking launched by the British, with Italian support, to take this island group in the Aegean Sea for use as bases against the German-controlled Balkans, but then wholly defeated by the Germans who, within two months, had secured the whole of the island group (8 September/22 November 1943).

The Dodecanese islands group lies in the south-eastern part of the Aegean Sea, just off the coast of Turkey, and had been under Italian control since the Italo-Turkish War in 1911. Under Italian rule, these strategically well-placed islands became a focus of Italian colonial ambitions in the eastern part of the Mediterranean Sea. The largest of the islands, Rhodes was developed as a major military and air base. The island of Léros, with its excellent deep-water port of Lakki (Portolago to the Italians), was transformed into a heavily fortified air base that was, as Benito Mussolini liked to boast, 'the Corregidor of the Mediterranean'. 'Abstention', which was an early British attempt to contest Italian control of the Dodecanese islands group, was thwarted in February 1941 when Italian forces recaptured the island of Kastellórizo from the British commandos whose had taken control of it.

After the German defeat of Greece in 'Marita' during April 1941 and the Allied defeat in the 'Battle of Crete' in the following month after the German 'Merkur' air- and sea-borne landings on this large island, Greece and its many islands were occupied by the Axis powers. With the defeat of Axis forces in the North African campaign in May 1943, Winston Churchill, the British prime minister, envisaged an operation to capture the Dodecanese islands group and Crete both to deprive the Axis of excellent forward bases in the Mediterranean Sea and to apply pressure on neutral Turkey to join the war on the Allied side. This tied nicely with one of Churchill’s long-favoured concepts, that of a 'route through the Dardanelles to Russia as an alternative to the Arctic convoys'. At the 'Symbol' conference in Casablanca during January 1943, approval was given and Churchill ordered his commanders to have plans ready by 27 January.

'Accolade' called for a direct attack on Rhodes and Kárpathos, using three infantry divisions, one armoured brigade and support units. Landings on Crete, which was too well fortified and had a strong German garrison, were dropped. The main problem faced by the planners was the difficulty of countering General Martin Fiebig’s X Fliegerkorps because of a lack of air cover, as British and US aircraft were based in Cyprus and the Middle East, and therefore out of range. This challenge was exacerbated by the demands of the Allies' forthcoming 'Husky' (i) invasion of Sicily. The USA was wholly sceptical about the operation, which it saw as being directed primarily at post-war political benefits for the UK and an unnecessary diversion from the Italian campaign. The Americans refused to support 'Accolade', warning the British that the latter would have to proceed without US manpower and matériel support.

As an Italian surrender became increasingly possible, in August 1943 the British prepared to take advantage of a possible split between the Italian and the Germans, in the form of a scaled-down version of 'Accolade'. A force based on Major General D. Russell’s Indian 8^th Division was assembled and US assistance, in the form of Lockheed P-38 Lightning twin-engined long-range fighter squadrons was requested. As a result of the 'Quadrant' first conference in Quebec during August 1943 and the US refusal to support the British plans, the forces and ships earmarked for 'Accolade' were diverted barely a week before Italy’s surrender in the Armistice of Cassibile on 8 September.

On the announcement of the armistice, the Italian garrisons of most of the Dodecanese islands group desired either to change sides and fight with the Allies or to go home. Anticipating the Italian armistice, German forces, based largely in mainland Greece, had been rushed to many of the islands to maintain control. The German forces were part of Generaloberst Alexander Löhr’s Heeresgruppe 'E', and the most important German force in the Dodecanese islands group was the 7,500-strong Sturmdivision 'Rhodos' under the command of Generalleutnant Ulrich Kleemann. This formation was formed during the summer on the island of Rhodes, which was the administrative centre of the Dodecanese islands group and possessed three military airfields. Because of this, Rhodes was the principal military objective for both sides.

On 8 September, the Italian garrison on the island of Kastellórizo surrendered to a British detachment, which was reinforced during the following days by ships of the Allied navies. The next day, a British delegation, headed by Major the Lord Jellicoe, was dropped by parachute on Rhodes to persuade the Italian commander, Ammiraglio di Squadra Inigo Campioni, to join the Allies. Swift action by the German forces forestalled the Allies: Kleemann attacked the 40,000-strong Italian garrison on 9 September and had forced it to surrender by 11 September. The loss of Rhodes dealt a critical blow to Allied hopes. Many Italian soldiers in the Aegean Sea area were tired of the war and had become opposed to Mussolini, but many Italian Fascist loyalists remained allied to Germany in the Greek campaign. The German forces in Greece convinced 10,000 Italians in the Aegean Sea area to continue to support their war effort.

Despite this setback, the British pressed ahead with the occupation of the other islands, especially the three larger ones of Kos, Sámos and Léros. The Germans were known to be overstretched in the Aegean Sea area, while the Allies enjoyed superiority at sea, and the air cover provided by the SAAF’s No. 7 Squadron and the RAF’s No. 74 Squadron, based on Kos and flying the Supermarine Spitfire single-engined fighter, was deemed adequate. It was hoped that from these islands, and with Italian co-operation, an assault could eventually be made on Rhodes. From 10 to 17 September, Brigadier F. G. R. Brittorous’s 234^th Brigade, coming from Malta, together with 160 men from the Special Boat Service, 130 men from the Long Range Desert Group, A Company of the 11/Parachute Regiment and Free Greek Sacred Band detachments had secured the islands of Kos, Kálymnos, Sámos, Léros, Sými, Kastellórizo and Astypálaia, supported by ships of the Royal Navy and the Free Greek navy. By 19 September, Kárpathos, Kásos and the Italian-occupied islands of the Sporades and Cyclades island groups were in German hands. On 23 September, Generalleutnant Friedrich-Wilhelm Müller’s 22^nd Luftlandedivision, which was garrisoning the 'fortress' of Crete, was ordered to take Kos and Léros.

Having identified the vital role of the only airfield on Kos for the British defence of the island, from 18 September the X Fliegerkorps bombed both it and the Allied positions on the island. Reinforcements gave the Germans 362 operational aircraft in the Aegean Sea area by 1 October. The British forces on Kos numbered about 1,500 men, 680 of whom were of the 1/Durham Light Infantry and the rest mainly RAF personnel, and about 3,500 Italians of the 10o Reggimento of Generale di Divisione Michele Scaroina’s 50a Divisione fanteria 'Regina'. On 3 October, the Germans effected their 'Eisbär' (v) amphibious and airborne landings, and reached the outskirts of Kos town later on the same day. The British withdrew under cover of night and surrendered on the next day. The fall of Kos was a major blow to the Allies, since it deprived them of air cover. The Germans took prisoner 1,388 British and 3,145 Italian men, and on 4 October committed the 'massacre of Kos', killing the captured Italian commander of the island, Colonnello Felice Leggio, and nearly 100 of his officers.

After the fall of Kos, the Italian garrison of Kálymnos surrendered, providing the Germans with a valuable base for operations against Léros. 'Leopard' (iii) was originally scheduled for 9 October, but two days before this ships of the Royal Navy intercepted and destroyed the German convoy headed for Kos. Several hundred men and most of the few German heavy landing craft were lost. Replacements were delivered by rail, and it was not until 5 November that the Germans had assembled a fleet of 24 light infantry landing craft. To avoid interception by the Allied navies, these landing craft were dispersed among several Aegean Sea islands and camouflaged. Despite Allied efforts to locate and sink the invasion fleet, as well as repeated shelling of the ports of German-held islands, the Germans suffered few losses and were able to assemble their invasion force, under the command of Müller, for 'Leopard' (iii) on 12 November.

The invasion force consisted of personnel from all branches of the German armed forces, including veterans of the 22^nd Luftlandedivision, one paratroop battalion and one Küstenjäger amphibious operations company of Generalmajor Alexander von Pfuhlstein’s Division 'Brandenburg' special operations formation. The Allied garrison of Léros comprised most of the 234^th Brigade with about 3,000 men of the 2/The Royal Irish Fusiliers under the command of Lieutenant Colonel Maurice French, the 4/The Buffs (The Royal East Kent Regiment), the 1/The King’s Own Royal Regiment (Lancaster) and the 2^nd Company of the 2/The Queen’s Own Royal West Kent Regiment, under the command of Brigadier R. A. G. Tilney, who assumed command on 5 November. There were also some 8,500 Italians, mostly naval personnel, under the command of Contrammiraglio Luigi Mascherpa.

Léros had been subjected to air attack by the Luftwaffe since 26 September, and this had caused significant casualties and damage to the defenders of the island and their supporting naval forces. In the early hours of 12 November, the invasion force in two groups approached the island from east and west. Despite failures in some areas, the Germans established a beach-head, while airborne forces landed on Mt Rachi in the middle of the island. After repulsing Allied counterattacks and being reinforced during the following night, the Germans quickly cut the island in two and the Allies surrendered on 16 November. The Germans suffered 520 casualties and took prisoner 3,200 British and 5,350 Italian soldiers.

Since the operational theatre was dominated by a host of islands, compelling both the Allies and Germans had to rely on naval vessels for reinforcement and supply, the naval component of the campaign was especially pronounced. Initially, the naval presence on each side was small, most of the Allied shipping and warships having been transferred to the central Mediterranean to support the operations in Italy, while the Germans did not have a large naval force in the Aegean Sea. The Germans possessed air superiority, which caused the Allies many losses in ships. Vizeadmiral Werner Lange, the Kommandierender Admiral Ägäis, tried to reinforce the isolated German garrisons and carry out operations against Allied garrisons, while also transporting Italian prisoners of war to the mainland. Allied ships tried to intercept the German ships, resulting in heavy losses. On 23 September, the destroyer Eclipse damaged the torpedo boat TA-10 and sank the steamer Gaetano Donizetti, which had 1,576 Italian prisoners of war on board. Another disaster occurred a month later, when USAAF North American B-25 Mitchell twin-engined bombers and RAF Bristol Beaufighter twin-engined heavy fighters sank the cargo ship Sinfra, which had 2,389 Italian and 71 Greek prisoners of war, as well as 204 German guards, on board, and only 539 of these were saved.

On 14 September, the first Allied loss occurred, when the Free Greek submarine Katsonis was rammed and sunk by the submarine hunter UJ-2101. The Luftwaffe also intervened on 26 September, when 25 Junkers Ju 88 twin-engined medium bombers sank the Free Greek destroyer Vasilissa Olga and the British destroyer Intrepid in Lakki Bay. On 1 October the Italian destroyer Euro was sunk and on 9 October the destroyer Panther was sunk and the light cruiser Carlisle was seriously damaged. At the same time, the short range of the 'Hunt' class escort destroyers Aldenham and Greek Pindos and Themistoklis prevented them from intercepting the German invasion convoy headed for Kos. Further losses on both sides followed, and after the loss of Kos and friendly air cover, the Allied naval element concentrated on supply missions to the threatened islands of Léros and Sámos, mostly under the cover of night. From 22 to 24 October, the escort destroyer Hurworth and destroyer Eclipse sank in a German minefield to the east of Kálymnos, while the Free Greek destroyer Adrias lost her bow. The ship escaped to the Turkish coast and, after makeshift repairs had been completed, steamed to Alexandria.

On the night of 10/11 November, the destroyers Petard, Rockwood and Free Polish Krakowiak shelled the German positions on Kálymnos and the destroyer Faulknor bombarded Kos, where German forces were assembling for the attack on Léros. The German convoy reached Léros on 12 November, with a naval escort of more than 25 ships, most of them torpedo boats, submarine chasers and minesweepers. During the subsequent nights, Allied destroyers failed to find and destroy the German vessels, limiting themselves to bombarding the German positions on Léros. With the fall of Léros on 16 November, the Allied ships were withdrawn, taking with them the remaining British garrisons. By that time, the Germans had also used Dornier Do 217 twin-engined aircraft of Oberstleutnant Bernhard Jope’s Kampfgeschwader 100 to launch Henschel Hs 293 radio-controlled missiles, which scored two hits: one caused severe damage to the escort destroyer Rockwood on 11 November and another sank the escort destroyer Dulverton two days later. The Allies lost six destroyers sunk and two cruisers and two destroyers damaged between 7 September and 28 November.

After the fall of Léros, the British evacuated their forces on Sámos and the other smaller islands. The Germans bombed Sámos with Junkers Ju 87 single-engined dive-bombers of the I/Stukageschwader 3, based at Megara, prompting the 2,500-strong Italian garrison to surrender on 22 November. Along with the occupation of the smaller islands of Pátmos, Foúrnoi and Ikaría on 18 November, the Germans thus completed their conquest of the Dodecanese islands group, which they held for the rest of the war. Only the island of Castellórizo off the Turkish coast was held by the British, and was never threatened.

The Dodecanese islands group campaign was one of the last British defeats in World War II and one of the last German victories, while others have labelled it a hapless fiasco which was badly conceived, planned and executed as a 'shoestring strategy'. The Germans' victory was the result of their possession of air superiority, which caused great loss to the Allies, especially in ships, and enabled the Germans to supply their forces. The operation was criticised by many at the time as another useless Gallipoli-like disaster, and likewise laid the blame at Churchill’s door. This was perhaps unjust, for he had pushed for these efforts to be made far sooner and thus before the Germans were prepared.

The British failure to capture the Dodecanese islands sealed the fate of Jews living there. Although Italy had passed the anti-Jewish law of the Manifesto of Race in 1938, Jews living on the Dodecanese islands and in Italian-occupied Greece experienced considerably less anti-semitism than those in the parts of Greece occupied by the Germans and Bulgarians, which culminated in March 1943 with deportations to the death camps in occupied Poland. The Italian surrender, the German takeover and the failure of the Allied offensive meant that the haven disappeared. Most of the Dodecanese Jews were murdered by the Germans: 1,700 of some 2,000 members of the ancient Jewish community of Rhodes were seized by the Gestapo in July 1944 and only about 160 of them survived the camps. Of 6,000 Ladino-speaking Jews in the Dodecanese islands group, about 1,200 survived by escaping to the nearby coast of Turkey.

Italian prisoners of war were transferred to the Greek mainland by the Germans in overcrowded, unseaworthy vessels, which led to several accidents, of which the sinking of Oria on 12 February 1944 was the most deadly: more than 4,000 Italians died when the ship sank in a storm. Other ships were sunk by British forces. The revival of German fortunes in the eastern Mediterranean helped restore the confidence of General Francisco Franco y Bahamonde, the Spanish Falangist dictator, in the German war effort, shaken by the Allied landings in North Africa and Italy, and ensured the continued export, for several months, of Spanish tungsten for the German war industries.