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 referred to as a "twin-screw corvette", its aim was to improve upon the convoy escort fleets of the Royal Navy at that time, including the Flower-class corvette. The initial orders were placed by the Royal Navy in 1940 and the vessels bore names of rivers within the United Kingdom, thus defining this class.