Operation Barbarossa was the German code name for the plan to invade the USSR during the Second World War. It was launched on the 22nd of June 1941. The plan was initially successful but by the end of 1941, the German advance had stalled. Large sections of the USSR, particularly the Ukraine, remained in German hands until 1944 and fighting continued elsewhere until then, notably the sieges of Leningrad and Stalingrad. Research Operation Barbarossa