Germany's attack, also known as "Operation Barbarossa". Included invading moscow and taking USSR. Began with the seige of a town attached to russia by lake ledoga, which had huge war plants. This town suffered a harsh winter with limited materials because of a blockade, and eventually the german army retreated because of the terrible conditions. Lost the USSR's support for Germany in the war and boosted soviet morale. Sept 8 1941- jan 27 1944.