The Kronshtadt-class battlecruisers, with the Soviet designation as Project 69 heavy cruisers, (), were ordered for the Soviet Navy in the late 1930s. Two ships were started but none were completed due to World War II. These ships had a complex and prolonged design process which was hampered by constantly changing requirements and the Great Purge in 1937. They were laid down in 1939, with an estimated completion date in 1944, but Stalin's naval construction program proved to be more than the shipbuilding and armaments industries could handle. Prototypes of the armament and machinery had not even been completed by 22 June 1941, almost two years after the start of construction. This is why the Soviets bought twelve surplus SK C/34 guns, and their twin turrets, similar to those used in the B