Chagos Archipelago in the context of "Rodrigues"

The British Indian Ocean Territory (BIOT) is a British Overseas Territory situated in the Indian Ocean. The territory comprises the seven atolls of the Chagos Archipelago with over 1,000 individual islands, many very small, amounting to a total land area of 60 square kilometres (23 square miles). The largest and most southerly island is Diego Garcia, 27 square kilometres (10 square miles), the site of a Joint Military Facility of the United Kingdom and the United States. Official administration is remote from London, though the local capital is often regarded as being on Diego Garcia.

Mauritius claimed that the British government separated the Chagos Archipelago from Mauritius, creating a new colony, the British Indian Ocean Territory (BIOT). However, this was disputed by the United Kingdom, who said that the Chagos Islands had no historical or cultural ties to Mauritius, and that they were only governed during the colonial period from Mauritius (2191 km or 1361 miles away) as an administrative convenience. Mauritius further claimed that to avoid accountability to the United Nations for its continued colonial rule, the UK falsely claimed that the Chagos had no permanent population.

Seychelles (/seɪˈʃɛl(z)/ , /ˈseɪʃɛl(z)/; French: [sɛʃɛl] or [seʃɛl]), officially the Republic of Seychelles (French: République des Seychelles; Seychellois Creole: Repiblik Sesel), is an island country and archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, Victoria, is 1,500 kilometres (800 nautical miles) east of mainland Africa. Nearby island countries and territories include the Maldives, Comoros, Madagascar, Mauritius, and the French overseas departments of Mayotte and Réunion to the south; and the Chagos Archipelago to the east.Seychelles is the smallest country in Africa as well as the least populated sovereign African country, with an estimated population of 100,600 in 2022.

Seychelles was uninhabited prior to being encountered by Europeans in the 16th century. It faced competing French and British interests until it came under full British control in the early 19th century. Since proclaiming independence from the United Kingdom in 1976, it has developed from a largely agricultural society to a market-based diversified economy, characterised by service, public sector, and tourism activities. From 1976 to 2015, nominal GDP grew nearly 700%, and purchasing power parity nearly 1600%. Since the late 2010s, the government has taken steps to encourage foreign investment.

Diego Garcia is the largest island of the Chagos Archipelago. It has been used as a joint UK–U.S. military base since the 1970s, following the expulsion of the Chagossians by the UK government. The Chagos Islands is a British overseas territory, though a treaty to transfer sovereignty from the UK to Mauritius was signed on 22 May 2025, with a provision that the military base at the island would remain under British control for at least 99 years. The agreement may be renewed for an additional 40 years after the initial 99-year period, and for an additional period thereafter.

Located just south of the equator in the central Indian Ocean, Diego Garcia lies 3,535 km (2,197 mi) east of Tanzania, 2,984 km (1,854 mi) east-southeast of Somalia, 726 km (451 mi) south of the Maldives, 1,796 km (1,116 mi) southwest of India, 2,877 km (1,788 mi) west-southwest of Sumatra, 4,723 km (2,935 mi) northwest of Australia, and 2,112 km (1,312 mi) northeast of Mauritius Island. Diego Garcia is part of the Chagos-Laccadive Ridge, an underwater mountain range that includes the Lakshadweep, the Maldives, and the other 60 small islands of the Chagos Archipelago. The island observes UTC+6 year-round.

Mauritius, officially the Republic of Mauritius, is an island country in the Indian Ocean, about 2,000 kilometres (1,100 nautical miles) off the southeastern coast of East Africa, east of Madagascar. It includes the main island (also called Mauritius), as well as Rodrigues, Agaléga, St. Brandon (Cargados Carajos shoals) and the Chagos Archipelagos. The islands of Mauritius and Rodrigues, along with nearby Réunion (a French overseas department), are part of the Mascarene Islands. The main island of Mauritius, where the population is concentrated, hosts the capital and largest city, Port Louis. The country spans 2,040 square kilometres (790 sq mi) and has an exclusive economic zone covering approximately 2,000,000 square kilometres (580,000 square nautical miles).

The 1502 Portuguese Cantino planisphere has led some historians to speculate that Arab sailors were the first to discover the uninhabited island around 975, naming it Dina Arobi. Called Ilha do Cirne or Ilha do Cerne on early Portuguese maps, the island was visited by Portuguese sailors in 1507. A Dutch fleet, under the command of Admiral Van Warwyck, landed at what is now the Grand Port District and took possession of the island in 1598, renaming it after Maurice, Prince of Orange. Short-lived Dutch attempts at permanent settlement took place over a century aimed at exploiting the local ebony forests, establishing sugar and arrack production using cane plant cuttings from Java together with over three hundred Malagasy slaves, all in vain. When French colonisation began in 1715, the island was renamed "Isle de France". In 1810, the United Kingdom seized the island and under the Treaty of Paris, France ceded Mauritius and its dependencies to the United Kingdom. The British colony of Mauritius now included Rodrigues, Agaléga, St. Brandon, the Chagos Archipelago, and, until 1906, the Seychelles. Mauritius and France dispute sovereignty over the island of Tromelin, the treaty failing to mention it specifically. Mauritius became the British Empire's main sugar-producing colony and remained a primarily sugar-dominated plantation-based colony until independence, in 1968. In 1992, the country abolished the monarchy, replacing it with the president.

Isle de France (Modern French: Île de France, pronounced [il də fʁɑ̃s] ) was a French colony in the Indian Ocean from 1715 to 1810, comprising the island now known as Mauritius and its dependent territories. It was governed by the French East India Company and formed part of the French colonial empire. Under the French, the island witnessed major changes. The increasing importance of agriculture led to the "import" of slaves and the undertaking of vast infrastructural works that transformed the capital Port Louis into a major port, warehousing, and commercial centre.

During the Napoleonic Wars, Isle de France became a base from which the French navy, including squadrons under Rear Admiral Linois or Commodore Jacques Hamelin, and corsairs such as Robert Surcouf, organised raids on British merchant ships. The raids (see Battle of Pulo Aura and Mauritius campaign of 1809–1811) continued until 1810 when the British sent a strong expedition to capture the island. The first British attempt, in August 1810, to attack Grand Port resulted in a French victory, one celebrated on the Arc de Triomphe in Paris. A subsequent and much larger attack launched in December of the same year from Rodrigues, which had been captured a year earlier, was successful. The British landed in large numbers in the north of the island and rapidly overpowered the French, who capitulated (see Invasion of Isle de France). In the Treaty of Paris (1814), the French ceded Isle de France together with its territories including Agaléga, the Cargados Carajos Shoals, the Chagos Archipelago, Rodrigues, Seychelles, and Tromelin Island to the United Kingdom. The island then reverted to its former name, 'Mauritius'.

A marine park is a designated park consisting of an area of sea (or lake) set aside to achieve ecological sustainability, promote marine awareness and understanding, enable marine recreational activities, and provide benefits for Indigenous peoples and coastal communities. Most marine parks are managed by national governments, and organized like 'watery' national parks, whereas marine protected areas and marine reserves are often managed by a subnational entity or non-governmental organization, such as a conservation authority.

The largest marine park used to be the Great Barrier Reef Marine Park in Australia, at 350,000 km until 2010, when the United Kingdom announced the opening of the Chagos Marine Park or Chagos Archipelago.

The Salomon Islands or Salomon Atoll is a small atoll of the Chagos Archipelago.

Nelsons Island or Nelson Island or Île Legour is a small uninhabited island in the Great Chagos Bank, of the Chagos Archipelago in the Indian Ocean. As a protected nature reserve, access to the island is strictly restricted.

The island is administered by the British Indian Ocean Territory, an overseas territory of the United Kingdom, but is due to become part of Mauritius following a 2025 agreement.