The Germans thought that they would win the war in a matter of weeks, and certainly before the onset of winter, which everyone knew would hinder largescale operations. The codename for the German invasion was Operation Barbarossa in honor of Frederick I, the Holy Roman Emperor who organized a 12th century crusade to liberate the holy places of Christianity from the Muslim control. According to Nazi propaganda, the German campaign in Russia was of a similar character—a crusade against a Bolshevik regime that threatened European civilization.