In the spring of 1937, the Soviet authorities learned about the construction of new German and Japanese ships that seemed more powerful than their A-class battleship project. The Shipbuilding Bureau suggested improving the displacement and speed of Project 23 up to 55,000 tons and 29.5 knots, respectively. The project was completed in March 1938, and the Defense Committee ordered the construction of four more ships. Sovetsky Soyuz was laid down at the Baltic Works on July 15, 1938. When the war broke out, the orders for producing parts in foreign countries were canceled; the ship, which was 21% complete, wasnt finished due to the blockade of Leningrad.