 At around 3 : 15 am on 22 June 1941 , the Axis Powers commenced the invasion of the Soviet Union with the bombing of major cities in Soviet @-@ occupied Poland and an artillery barrage on Red Army defences on the entire front . The heavy air @-@ raids reached as far as Kronstadt near Leningrad , Ismail in Bessarabia , and Sevastopol in the Crimea . Meanwhile , ground troops crossed the border , accompanied in some locales by Lithuanian and Ukrainian fifth columnists . Roughly three million soldiers of the Wehrmacht went into action and faced slightly fewer Soviet troops at the border . 
