Diego Garcia is an atoll just south of the equator in the central Indian Ocean, and the largest of 60 small islands comprising the Chagos Archipelago. It was settled by the French in the 1790s and was transferred to British rule after the Napoleonic Wars. It was one of the "Dependencies" of the British Colony of Mauritius until it was detached for inclusion in the newly created British Indian Ocean Territory in 1965. The atoll is located 3,535 km east of Tanzania's coast, 1,796 km south-southwest of Kanyakumari (India) and 4,723 km west-northwest of the west coast of Australia.
The uninhabited islands are asserted to have been discovered by the Portuguese navigator, explorer, and diplomat Pedro Mascarenhas in 1512, first named as Dom Garcia, in honour of his patron, Dom Garcia de Noronha. Another Portuguese expedition with a Spanish explorer of Andalusian origin, Diego García de Moguer, rediscovered the island in 1544 and named it after himself.
Most inhabitants of Diego Garcia through the period 1793–1971 were plantation workers, but also included Franco-Mauritian managers, Indo-Mauritian administrators, Mauritian and Seychellois contract employees, and in the late 19th century, Chinese and Somali employees. Between 1968 and 1973, the population was forcibly removed by the United Kingdom and the United States to establish an American base through intimidation of locals and denying the return of any who left the island. Many were deported to Mauritius and the Seychelles, following which the United States built a large naval and military base.