The Imperial Japanese Navy was an early proponent of naval air power and commissioned the world’s first purpose-designed aircraft carrier, the Hosho, in 1922. There followed a series of one-off designs of widely different sizes, some converted from capital ships, some designed as such from scratch, but no two of them alike until the Shokaku class completed just before the outbreak of the Pacific War. As with much Japanese warship design in the 1930s, these ships often exhibited highly original thinking, with some unique experiments like placing the island on the port side in a couple of ships. Following the attack on Pearl Harbor, Japanese carrier forces dominated the naval war but the catastrophic losses at Midway in June 1942 forced the IJN into many makeshift measures to rebuild carrier numbers, including converting both naval auxiliaries and merchant ships, and producing an austere design of fleet carrier intended for series production. The technical characteristics of all these 29 ships are covered by individual chapters in this book, illustrated with plans, photos and colour artwork. There is a general introduction to naval aviation policy and a summary of the carrier actions in the Pacific War, with appendices on weaponry, radar, camouflage schemes and naval aircraft. Despite the importance of Japanese aircraft carriers, they are not well covered in English, so this book, with its wealth of detail in a concise format, fills a real need.