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.

The U.K. has agreed to hand sovereignty of the long-contested Chagos Islands, an archipelago of more than 60 islands in the Indian Ocean, to Mauritius, in a deal to secure the future of a strategically important U.