What was the codename for Germany's invasion of the Soviet Union in 1941?

The codename for Germany’s 1941 invasion of the Soviet Union was Operation Barbarossa.

The invasion began on June 22, 1941, when German and allied Axis forces attacked across a front roughly 2,900 kilometers wide. It opened the Eastern Front, the largest and deadliest theater of World War II. Germany expected the Soviet Union to collapse quickly, but the Red Army continued fighting despite enormous early losses.

The name referred to Frederick I, Holy Roman Emperor, known as Barbarossa (“Red Beard”). German planners had initially used the codename Operation Otto, but Adolf Hitler changed it in December 1940. The name reflected Nazi ambitions to conquer territory, destroy Soviet communism, seize agricultural and mineral resources, and create a German-dominated empire in Eastern Europe.

A common mix-up is Operation Typhoon, the later 1941 German offensive aimed at Moscow. Operation Citadel was the 1943 Battle of Kursk, while Weserübung was Germany’s 1940 invasion of Denmark and Norway.