IJN Shinano (Japanese: 信濃) was the lead ship of the Shinano-class aircraft carriers of the Imperial Japanese Navy (IJN). Originally laid down in 1940 as the third Yamato-class battleship, Shinano was converted to an aircraft carrier during construction due to Japan's losses in the Pacific War. The ship was launched in November 1944 and commissioned in November 1944. She was sunk en route to her combat station in the Philippines by a submarine attack on 29 November 1944, with the loss of over 1,400 men. Shinano was designed as a battleship with the heaviest possible armament and armor. After her conversion to an aircraft carrier, she was the largest warship ever built, displacing more than 72,000 tons. Shinano was equipped with a flight deck that could accommodate up to 100 aircraft, and her hangars could hold an additional 120 aircraft. She was also armed with a powerful anti-aircraft battery. Shinano was intended to be a mobile aircraft carrier that could support the IJN's carrier fleet. She was also intended to be used as a flagship for the IJN's Combined Fleet. However, Shinano was only operational for a few weeks before she was sunk. Her loss was a major blow to the IJN, and it contributed to the Japanese defeat in the Pacific War. The wreck of Shinano was discovered in 2017. She is currently being surveyed by Japanese and American researchers. The wreck is in relatively good condition, and it is expected to provide valuable information about the design and construction of Shinano. Shinano was the last battleship built by the IJN. Her loss marked the end of the Japanese battleship era.