Angus Konstam 
British Light Cruisers 1939 45 [PDF ebook] 

The light cruiser was a natural development of the sailing frigate a fast multi-purpose warship that could patrol the sea lanes, protect convoys and scout for enemy battle fleets. By the inter-war period the need for this type of ship was even more important, given the increasing need for protection from aircraft, and the need to screen the fleet from submarines or destroyers. Wartime experience had shown that the British light cruiser was one of the most versatile types of ship in the Royal Navy, able to protect other warships, bombard enemy shores, guard life-saving convoys and intercept and destroy enemy warships. These were truly the workhorses of the wartime Royal Navy. While the battleships and carriers grabbed the headlines, these sleek, elegant warships quietly got on with the job of securing control of the seas.