The island was ceded to Britain together with Hong Kong Island. A small fort was built on it in 1841 for the protection of the eastern section of Victoria Harbour, and a battery with three cannons was added in 1854. The island was renamed in the 1860s (some sources mention 1842) after the naval officer Sir Henry Kellett. Kellett Bay and Mount Kellett were also named after him. After Kowloon Peninsula was ceded to Britain in 1860, the defense position of Kellett Island declined in importance, and it was used by British armed forces for ammunition and gunpowder storage.