Soviet combat vehicle production during World War II from the start of the German invasion of the Soviet Union on 22 June 1941 was large. Although the Soviet Union had a large force of combat vehicles before the German invasion, heavy losses led to a high demand for new vehicles. Production was complicated by the loss of production facilities in the western part of the Soviet Union, and entire factories were moved east of the Ural Mountains to put them out of reach of the Germans. Soviet industrialization in the pre-war years (starting in the 1920s) had been rapid, but quantity was given priority over quality and Soviet engineers were comparatively inexperienced as the Soviet Union started off as a primarily agricultural society. Therefore, the quality of Soviet combat vehicles was inferio