One side in this campaign decided to march northwards because of the Lossberg Study. This campaign was revived a year later in Operation Little Saturn, part of a continuation called Case Blue. This campaign's goal was to establish a line of demarcation stretching from Arkhangelsk to Astrakhan. Georgy Zhukov led the victors during its turning point, which came during a harsh winter. This campaign is named after a red-bearded Holy Roman Emperor, and effectively ended the Molotov-Ribbentrop Pact. It ended after the bloody Siege of Stalingrad. For 10 points, name this 1941
One side in this campaign decided to march northwards because of the Lossberg Study. This campaign was revived a year later in Operation Little Saturn, part of a continuation called Case Blue. This campaign's goal was to establish a line of demarcation stretching from Arkhangelsk to Astrakhan. Georgy Zhukov led the victors during its turning point, which came during a harsh winter. This campaign is named after a red-bearded Holy Roman Emperor, and effectively ended the Molotov-Ribbentrop Pact. It ended after the bloody Siege of Stalingrad. For 10 points, name this 1941 operation in which Hitler failed to take a nation led by Joseph Stalin.         
One side in this campaign decided to march northwards because of the Lossberg Study.
Operation Barbarossa [or Fall Barbarossa; or Case Barbarossa; or Germany's invasion of the USSR; or Hitler's invasion of Soviet Russia or similar answers before the end]  