Until 1965, the United Kingdom (UK) governed a group of islands in the Indian Ocean called the Republic of Mauritius and its dependencies. Small islands and atolls nearby comprised a Mauritius dependency called the Chagos Archipelago. The largest was Diego Garcia, a tiny island of about 10 square miles comprising more than half the archipelago’s total land area. Because the US wanted to build military facilities on Diego Garcia, the UK split off the Chagos Archipelago and established a new colony before granting Mauritius independence. The UK agreed with the US to resettle any inhabitants of the Chagos Archipelago elsewhere. Known as Chagossians, the UK forcibly removed the entire population of the Chagos Archipelago or prevented them from returning over a five-year period. Meanwhile, Mauritius gained independence in 1968 and admittance to the United Nations (UN) without the Chagos Archipelago. Mauritius’s new prime minister told its parliament that they its people had no choice. The UN General Assembly asked the International Court of Justice to issue an advisory opinion as to whether the UK lawfully completed Mauritius’s decolonization and the legal consequences of continuing to administer the Chagos Archipelago, particularly for resettling displaced Mauritian nationals and Chagossians there.