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.

Britain struck a deal allowing it to keeping control of a strategically important UK-US military base in the Indian Ocean for another century, while ceding sovereignty over the Chagos Islands to Mauritius.

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.