Originally called a "twin-screw corvette", its purpose was to improve on the convoy escort classes in service with the Royal Navy at the time, including the Flower-class corvette. The first orders were placed by the Royal Navy in 1940 and the vessels were named for rivers in the United Kingdom, giving name to the class.
Originally called a "twin-screw corvette", its purpose was to enhance the convoy escort fleets then in service with the Royal Navy, including the Flower-class corvette. The first orders were placed by the Royal Navy in 1940 and the ships were named after rivers within the United Kingdom, thereby establishing this class.