German invasion of the Soviet Union that opened World War II on the Eastern Front, commencing the largest, most bitterly contested, and bloodiest campaign of the war. Adolf Hitler's objective for Operation Barbarossa was simple: he sought to crush the Soviet Union in one swift blow. With the USSR defeated and its vast resources at his disposal, surely Britain would have to sue for peace. So confident was he of victory that he made no effort to coordinate the invasion with his Japanese ally. Hitler predicted a quick victory in a campaign of, at most, three months.
taken from - Spencer C. Tucker et al., eds., Encyclopedia of World War II: A Political, Social, and Military History (Santa Barbara: ABC-CLIO, 2005), 180.