Kaga Country: Japan Type: Aircraft carrier Service: 1929 - 1942 Laid down: 19 July 1920 (as a battleship) Launched: 17 November 1921 (as a battleship) Commissioned: 1 November 1929 (as an aircraft carrier) Struck: 10 August 1942 Fate: Sunk 4 June 1942

Kaga was an aircraft carrier of the Imperial Japanese Navy. The Kaga was the only ship of the class. Kaga began as a Tosa class battleship, and was launched on 17 November 1921 at the Kawasaki Heavy Industries shipyard in Kobe. On 5 February 1922 both Tosa class ships were cancelled and designated for scrapping under the terms of the Washington Naval Treaty. The treaty authorized conversion of two battleship or battlecruiser hulls into aircraft carriers of up to 33,000 tons standard displacement. The incomplete battlecruisers Amagi and Akagi were initially selected, but an earthquake damaged the Amagi hull beyond economic repair. Kaga was therefore selected for completion as an aircraft carrier.

The conversion into an aircraft carrier began in 1923 and lasted until 1928. Upon completion, Kaga underwent trials for another two years before becoming operational. Design problmes led to Kaga commencing a second major reconstruction in 1934. Kaga returned to service in 1935.

During the late 1930s Kaga supported operations in China, and was involved in the Shanghai Incident and during the early years of the Second Sino-Japanese War. At the beginning of World War II, she took part in the attack on Pearl Harbor. The Kaga continued operations against Allied forces until she was sunk at the Battle of Midway on 4 June 1942.