Japanese aircraft carrier Hōshō becomes the first purpose built aircraft carrier to be commissioned in the world.
Hōshō (鳳翔, literally "phoenix flying") was the world's first commissioned ship that was built as an aircraft carrier, and the first aircraft carrier of the Imperial Japanese Navy (IJN). Commissioned in 1922, the ship was used for testing carrier aircraft operations equipment, techniques, such as take-offs and landings, and carrier aircraft operational methods and tactics. The ship provided valuable lessons and experience for the IJN in early carrier air operations. Hōshō's superstructure and other obstructions to the flight deck were removed in 1924 on the advice of experienced aircrews.
Hōshō and her aircraft group participated in the Shanghai Incident in 1932 and in the opening stages of the Sino-Japanese War in late 1937. During those two conflicts, the carrier's aircraft supported Imperial Japanese Army ground operations and engaged in aerial combat with aircraft of the Nationalist Chinese Air Force. The small size of the ship and her assigned airgroups (usually around 15 aircraft) limited the effectiveness of her contributions to combat operations. As a result, the carrier was placed in reserve after her return to Japan from China and she became a training ship in 1939.
During World War II, Hōshō participated in the Battle of Midway in June 1942 in a secondary role. After the battle, the carrier resumed her training role in Japanese home waters for the duration of the conflict and survived the war with only minor damage from air attacks. She was surrendered to the Allies at the end of the war and used to repatriate Japanese troops until she was scrapped in 1946.