The last major campaign in which the Panzer I formed a large portion of the armored strength was Operation Barbarossa, 22 June 1941. The 3,300 German tanks included about 410 Panzer I's. By the end of the month, a large portion of the Red Army found itself trapped in the Minsk pocket, and by 21 September Kiev had fallen, thereby allowing the Germans to concentrate on their ultimate objective, Moscow.