Britain will hand over sovereignty of the Chagos Islands in the Indian Ocean to Mauritius while retaining delegated sovereignty over Diego Garcia, a joint British American military base Britain withheld when granting Mauritius independence in 1968.

The agreement ends decades of dispute over Britain’s last African colony, from which thousands of people were forcibly evicted, while maintaining a key U.S.-British military base there.

After years of legal wrangling and negotiations, Britain said it would surrender sovereignty of the archipelago in the Indian Ocean.