In 1965, as part of the decolonisation process, the UK separated the islands from Mauritius, creating a new colony. From 1968 (when Mauritius gained independence), the UK expelled Chagossians from the islands to pave the way for a US military base it agreed on in 1966.

The British government made the deal to return all the Chagos Islands, except for Diego Garcia, which holds a U.K.-U.S. Navy base.

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