During the 31 years that the Italians remained in Leros, they set up a great plan to build and fortify the island, since its strategic position and its large natural harbours (the largest of which, Lakki, is the largest deep water harbour in the Mediterranean Sea), made it an ideal naval base. The fortification of Leros and the creation of a major naval base at Lakki, ensured that the Italians had control over an area of vital interest to the Allies (the Aegean, the Dardanelles and the Near East). Mussolini, who called Leros "the Corregidor of the Mediterranean", saw the island as a crucial base for the Italian domination of the eastern Aegean Sea, and even built a mansion for himself in the town of Portolago.
World War II
From 1940, when Italy entered the Second World War on the side of Germany, Leros suffered bombing raids by the British Royal Air Force. As a result of the excellent anchorage provided to warships by the many natural coves, the island was the second most bombed during World War Two (after Crete). On 8 September 1943, as Italy could not continue the war on the German side, it signed an armistice and came over to the Allied camp. After the Italian armistice, British reinforcements arrived on Leros and other Dodecanese islands and the island suffered continuous German aerial bombardment. One of the largest attacks was on the Greek Navy's flagship, the Queen Olga, sunk by German bombers on Sunday September 26, 1943, along with HMS Intrepid, while they were anchored in Portolago. The island of Leros was finally captured by German troops during operation Taifun in airborne and amphibious assaults between 12–16 November 1943. The forces involved were paratroop units and a battalion from the elite Brandenburg division. The ground troops were supported by bombers of the Luftwaffe. Among them I. and II. group of Stuka-Wing 3. I. Group operated from Megara Air Base. The island remained under German occupation
