Italian plans to invade Malta by sea began during the Second Italo-Abyssinian War (3 October 1935 – May 1936). An opportunity to capture Malta occurred in April 1941 but Operation Mercury (20 May – 1 June 1941), the invasion of Crete, was conducted first, with such losses of parachute troops and transport aircraft that a second operation in 1941 was impossible. Luftwaffe units apart from then went east for Operation Barbarossa and by June 1941, the island air defences had recovered. Luftwaffe units returned to the Mediterranean in spring 1942 and managed to neutralise the offensive capacity of the island garrison. In April, Hitler and Mussolini agreed to mount , an Italian-German air and sea invasion. Two with hundreds of Junkers Ju 52 transport aircraft, gliders (including 24 Messerschmitt Me 321 ) and about 200 transport aircraft were assembled for the invasion.