It was rebuilt by British forces in the 1760s, around an earlier Spanish fort, the Castell de Sant Felip, which had been established about 1554.
It is best known for its unsuccessful defence on two occasions by the British: during the Siege of Fort St Philip (1756) and the Invasion of Minorca, 1781.
With its commanding position overlooking the entrance to Mahon harbour the area around the fort was considered a good location for a lighthouse, and in 1852 one was built on the Sant Carles point.
[1] The keepers of the lighthouse were warned when firing practice was to take place but they complained that the shells damaged the building and alarmed their families.
The situation continued until 1912, when the lighthouse was closed and replaced with a moveable light on a metal davit.