The Yamato class was built after the Japanese withdrew from the Washington Naval Treaty at the Second London Conference of 1936. The treaty, as extended by the London Naval Treaty of 1930, forbade signatories to build battleships before 1937. Design work on the class began in 1934 and after modifications the design for a 68,000 ton vessel was accepted in March 1937. Yamato was built in intense secrecy at a specially prepared dock to hide her construction at Kure Naval Dockyards beginning on 4 November 1937. She was launched on 8 August 1940 and commissioned on 16 December 1941. Originally, five ships of this class were planned. Yamato and Musashi were completed as designed. The third, Shinano, was converted to an aircraft carrier during construction after the defeat at the Battle of Midway. The un-named “Hull Number 111” was scrapped in 1943 when roughly 30% complete, and “Hull Number 797”, proposed in the 1942 5th Supplementary Program, was never ordered. At the Kure Navy Yard, the construction dock was deepened, the gantry crane capacity was increased to 100 tonnes, and part of the dock was roofed over to prevent observation of the work. Many low-level designers and even senior officers were not informed of the true dimensions of the battleship until after the war. When the ship was launched, there was no commissioning ceremony or fanfare.
Yamato and Musashi made little direct impact during the war. The Musashi did not engage any Allied battleships during the war, yet the Yamato did have limited success when in October 1944 she opened fire on US escort carriers and destroyers. It was the first and last of her battles with enemy ships. She fired a total 104 rounds of 46cm projectiles as a result of which one escort carrier and one destroyer were sunk.
The end of Yamato was even less glorious. Having seen little action during the previous four years (she served as Yamamoto’s flagship during the Midway operation, as well as Kurita’s during the action off Samar on 25 October 1944) she was sent on a planned suicide mission against the U.S. Navy forces massing for the attack on Okinawa. On April 7, 1945 she was hit by successive waves of U.S. carrier based aircraft and sank after absorbing 8 bombs and at least 13 torpedo hits. Fewer than 300 out of 3,332 crew onboard survived.