The building of the Edgar at the yard of Vickers-Armstrong at Newcastle-on-Tyne as part of the Colossus-class was ordered on 14 March 1942. Originally she was to be a light fleet aircraft carrier however the British Admiralty decided in 1944 that she was to be converted into a aircraft maintenance carrier and in July of the same year that she was to be named Perseus. Laid down on 1 January 1943, she was launched on 26 March a year later and completed on 19 October 1945. In 1950 was she fitted out with a experimental steam catapult on top of her flight deck causing the removal of the deckhouse to port of the island. After a long range of tests and demonstrations was in 1952 the catapult again removed and she was converted into a ferry carrier. Three years later started the conversion at Belfast, Ireland into a submarine depot ship to be stopped in in 1957 as a result of lacking finances causing a sell in May 1958 to be broken up.
With a displacement of 12,265 long tons/12,462 tons (standard)-16,500 long tons/16,800 tons (deep load) were her dimensions 695’x 80’4’ x 23’ (deep load) or 211,8 x 24,49 x 7,0 metres. The 2 Parsons geared steam turbine sets and 4 Admiralty water-tube boilers supplied 40,000 shp allowing a speed of 25 knots or with a speed of 14 knots a range of 12,000 nautical miles. Her crew numbered 1,076 men. She was armed with 6x4-2pdr anti aircraft guns and 19x1-4cm Bofors anti aircraft guns.
