The French term Escorteur (Escort Ship) appeared during the Second World War to designate a warship, of a medium or light displacement, whose mission was to protect ocean convoys and naval squadrons from attacks by submarines. This role was in general handled by a destroyer escort such as the Buckley and Cannon classes built in the United States, or a Hunt-class destroyer built by the United Kingdom, or even a River class built by the United Kingdom, Canada and Australia. The Imperial Japanese Navy used the denomination of Kaibokan for this type of naval ship.