She was a member of the third subgroup of the class, and saw service in the Second World War, before being sunk by German E-boats in 1942.

Penylan was ordered on 23 August 1940 under the 1940 War Emergency Programme from Vickers-Armstrongs, Barrow-in-Furness.

She was adopted by the civil community of the Borough and Rural District of Carmarthen as part of Warship Week during 1942.

She had to put into a commercial shipyard in London on 22 October after a number of defects came to light.

She was under repair until 9 November when she sailed to Portsmouth and joined the 1st Destroyer Flotilla on patrol in the English Channel.