During the same month as the landings in French North Africa, the German drive for Egypt ended with their defeat at the Battle of El Alamein in November 1942. These events led Germany to disregard the territorial integrity of Vichy France and occupy southern France, thereby protecting the southern coast against invasion. This action by Germany, in turn, led the Vichy French to scuttle their fleet at Toulon, preventing it from being used by the Axis. As land battles continued across North Africa, escort carriers regularly accompanied convoys that ferried aircraft to Casablanca as well as Gibraltar and on to Malta to support the Allied advance and to help establish air superiority. Allied cruiser and destroyer striking forces, the Allied submarine fleet operating from Malta, and aircraft from Malta and Bone in Algeria gained control of the narrows in the Mediterranean between Italy and Africa. This choked off supplies to the Axis forces in Africa. Over 500 Axis merchantmen were sunk between January and mid-May 1943, when the last Axis soldiers surrendered. U-boat presence in the Mediterranean was dramatically reduced, in part by constant air patrolling that denied U-boats the opportunity to safely surface and recharge their batteries.