Campania was intended to be a refrigerated cargo ship when her keel was laid down on 12 August 1941 in the Belfast dockyard of Harland & Wolff.
While still in the stocks, she was requisitioned by the British Government in 1942 as part of the country's war effort.
She was one of five merchant vessels that were converted into escort carriers, joining HMS Nairana (the lead ship of the Royal Navy's Nairana-class), HMS Activity, HMS Pretoria Castle and HMS Vindex.
The escort carriers were designed to protect convoys of merchant ships from U-boat and aircraft attacks.
Campania was the first British carrier to be fitted with Action Information Organisation (AIO) and a Type 277 Radar able to detect low-level aircraft.
Entering service in early 1944, Campania spent the last year of the war conducting Arctic convoys to Russia.
On board she had 813 Naval Air Squadron, equipped with 12 Swordfish Mk III, four Grumman Wildcats and three Fairey Fulmars.
In December 1944, when paired with Nairana on an Arctic convoy, her Swordfish aircraft sank the German submarine U-365.
After the war, Campania was briefly used to transport aircraft, before being placed in reserve in December 1945.
In 1951, still with her escort carrier configuration and a civilian crew, she was used as the Festival of Britain's exhibition ship.
Campania toured the UK with a smaller version of the main South Bank exhibition.
Officially named the Sea Travelling Exhibition, she was repainted white, the ship was decorated with skeleton masts and bunting.
The ship visited Southampton, Dundee, Newcastle, Hull, Plymouth, Bristol, Cardiff, Belfast, Birkenhead and Glasgow, staying at each port for 10 to 14 days.
In 1952, Campania was the fleet flagship for Operation Hurricane, Britain's first test of the atomic bomb in the Montebello Islands in Australia.
The ship required a refit for the role with workshops, laboratories, offices, and cabins installed.
She also had a desalination plant added as the Montebello Islands had no freshwater source to supply the 1,500 personnel overseeing the operation.
Campania escorted HMS Plym, the vessel where the bomb was to be detonated, on the journey to Australia.
The test was successfully carried out on 3 October 1952.
On her return to the UK, Campania was decommissioned in December 1952 and scrapped in Blyth in 1955.
Cover image: HMS Campania at anchor in 1944 (Picture: Volgi archive/Alamy Stock Photo).