The Gambia was a British Colony between 1821 and 1965. There were modest coastal defence batteries built to protect the main harbour at Bathurst, now called Banjul. Bathurst was made the capital in 1889 after a joint project with the French in 1891 established the boundary between The Gambia and the adjacent French controlled Senegal. A small British Garrison was established in Bathurst.
These smooth bore coastal defence batteries were concentrated in Bathurst and Barra, covering the mouth of the River Gambia. James Island with Fort Gambia was the principal British position in the 18th and early 19th Century before Bathurst was developed. The old fort at Barra was rearmed with more modern weapons until 1945.