HMS Bulwark was laid down in Belfast on 10 May 1945. She was launched on 22 June 1948, but was not commissioned into the Royal Navy until 4 November 1954

In 1956, Bulwark took part in her first operation, during the Suez Crises, when she launched up to 600 sorties in what was then known as Operation Muskateer.

The fixed wing complement that embarked in 1957 comprised Sea Hawks, Sea Venoms, Gannets, Skyraiders and Whirlwind helicopters.

 In 1958 she paid off for conversion into a commando carrier. Her sister ship, HMS Albion, did likewise in 1961.

In 1960, Bulwark was recommissioned with 42 CDO RM and 848 Squadron attached to the carrier. In 1961, due to an increasing threat of invasion of Kuwait by Iraq, Bulwark landed 42 Commando in Kuwait. In the same year, she became the first Royal Navy warship since WWII to commission outside the UK commissioning instead in Singapore.

In 1967, she again commissioned in Singapore, and following her work up, proceeded to Aden to cover the withdrawal and relieve Albion. By this time, Bulwark '​s nickname "The Rusty B" had become firmly established.

In Spring 1969, with commanding officer Captain J.A. Templeton-Cotill (who would later become a rear admiral and Flag Officer Malta), Bulwark left for the Mediterranean. She returned to Devonport for decommissioning in late 1969.  In January 1970, Bulwark recommissioned and sailed to Singapore. After a minor refit in Singapore Naval Dockyard (to repair damage sustained in Tropical Storm Diane after leaving Cape Town), the ship sailed for Kobe, Japan, Hong Kong and Perth before returning to Plymouth.

In September 1971 Bulwark took part in exercises in the eastern Mediterranean with 845 Squadron embarked. While close to the coast of Yugoslavia in December, she suffered a boiler room fire, in 'B' boiler room, and limped home on one set of boilers. The repairs were started in Plymouth by the dockyard but were then completed in Malta by the ships own company.

In 1972, Bulwark, like her sister ship Albion, was involved in withdrawals across the declining empire. In 1972 she was headquarters ship for the withdrawal from Malta, an emotional withdrawal for the Royal Navy. Bulwark lay in Grand Harbour for 11 weeks and flew more than 1,000 missions.

In March 1976, Bulwark was withdrawn from service and placed in Reserve. Also during this year the Ministry of Defence offered Bulwark to the Peruvian Navy. After two years of negotiations finally the Royal Navy decided to keep the ship. Furthermore, she underwent a refit at Portsmouth in 1978, and was recommissioned as an anti-submarine warfare carrier on 23 February 1979.

Bulwark was involved in trials of the Sea Harrier. At the start of 1980, Bulwark visited the United States of America; participating in Exercise Safe Passage off the east coast of the United States in late February.  The carrier returned to Portsmouth on 2 April.

She was finally declared for disposal in April 1983. She remained anchored in harbour until she was towed from Portsmouth to be scrapped in April 1984.