sentences:  27 cavalry divisions were formed during the war, of which all but eleven were disbanded after the end of the war in 1921.The Red Army's cavalry forces was gradually expanded during the interwar period, reaching a peak in 1936, when the Red Army included 36 cavalry divisions.However, the increasing demand for mechanized units resulted in drastic reductions in the Red Army cavalry force during the last few years before the German invasion of the Soviet Union in June 1941.