In the late 1930s, the Soviets began an ambitious plan of naval expansion in reaction to the naval construction program already begun by Nazi Germany. The centerpiece of this plan was a total of 16 very large battleships. Only four of these ships were begun, and one had already been cancelled, before Nazi Germany invaded the Soviet Union in June 1941. Construction was suspended during the war and all four hulls were scrapped in the late 1940s.