What was the codename for the German invasion of Russia in World War II?

Operation Barbarossa was the code name for the Axis powers invasion of the Soviet Union, starting Sunday, 22 June 1941, during World War II. The operation stemmed from Nazi Germany's ideological aims to conquer the western Soviet Union so that it could be repopulated by Germans, to use Slavs as a slave-labour force for the Axis war-effort, and to seize the oil reserves of the Caucasus and the agricultural resources of Soviet territories.

Operationally, German forces achieved major victories and occupied some of the most important economic areas of the Soviet Union, mainly in the Ukrainian Soviet Socialist Republic, and inflicted, as well as sustained, heavy casualties. Despite these Axis successes, the German offensive stalled in the Battle of Moscow and subsequently the Soviet winter counteroffensive pushed German troops back. The Red Army absorbed the Wehrmacht's strongest blows and forced the unprepared Germans into a war of attrition. The Wehrmacht would never again mount a simultaneous offensive along the entire strategic Soviet–Axis front.