What was the code name for the German invasion of the Soviet Union in WW2?

The story behind the answer

Operation Barbarossa was the code name for Nazi Germany’s invasion of the Soviet Union, launched 22 June 1941. It was the largest land invasion in history, meant to destroy the Red Army, seize resources, and crush Bolshevism, breaking the Nazi-Soviet Pact. Named after the medieval emperor Frederick Barbarossa, it drove toward Leningrad, Moscow, and Ukraine but stalled from vast distances, poor logistics, fierce Soviet resistance, and winter—setting up turning points like Moscow and Stalingrad.

Memory tip: Barbarossa = “barbaric rush east,” and the emperor’s red beard links to the USSR’s “Red” identity. The other options: Molotov was the Soviet foreign minister (not a German operation); Operation Unthinkable was Churchill’s 1945 hypothetical plan against the USSR; Kaiserschlacht was a World War I German spring offensive.