The British Indian Ocean Territory (BIOT) includes the seven atolls of the Chagos Archipelago, located south of the Equator near the center of the Indian Ocean. These islands were formerly administered as a dependency of Mauritius. They were detached as a separate colony in 1965 so that Britain and the U.S. could establish a military base on Diego Garcia, the largest atoll of the group. In 1966 the U.S. leased this base, now called the U.S. Naval Support Facility Diego Garcia. The lease has been extended to 2036.
Former residents of the islands were displaced to Mauritius and Seychelles. In 2000 the British High Court ruled that they have the right in principle to return, and in 2006 the islanders were granted the right to visit their former homes for purposes such as tending the graves of their ancestors.
In 2017 the United Nations General Assembly voted to refer the territorial dispute between Mauritius and the United Kingdom to the International Court of Justice. The Court held hearings on the case in September 2018 and in February 2019 the Court found the separation of the Chagos Archipelago to be unlawful and found that the United Kingdom is obliged to end "its administration of the Chagos Islands as rapidly as possible." The International Tribunal for the Law of the Sea ruled in January 2021 that the United Kingdom has no sovereignty over the Chagos and that Mauritius is sovereign there.
Although Britain has promised to return control to Mauritius if the islands are no longer needed for defense purposes this seems quite unlikely to happen in the foreseeable future.
Aids to navigation at Diego Garcia are maintained by the U.S. Navy.
ARLHS numbers are from the ARLHS World List of Lights. Admiralty numbers are from volume Q of the Admiralty List of Lights & Fog Signals. U.S. NGA List numbers are from Publication 112.
Adjoining pages: North: Maldives | South: Mauritius | West: Seychelles
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Posted November 16, 2005. Checked and revised April 8, 2022. Lighthouses: 3. Site copyright 2022 Russ Rowlett and the University of North Carolina at Chapel Hill.