British Indian Ocean Territory

The British Indian Ocean Territory (BIOT) is a British Overseas Territory in the Indian Ocean. It has seven atolls called the Chagos Archipelago. These atolls have over 1,000 small islands and cover 60 square kilometres (23 square miles). The biggest island is Diego Garcia. An important Joint Military Facility is there, shared by the United Kingdom and the United States.

There has been a disagreement between the United Kingdom and Mauritius. Mauritius thinks the islands were taken away unfairly. The UK disagrees. In the late 1960s and early 1970s, about 2,000 people who lived there were moved so the military base could be built. These people are called Chagossians, and they want to return home.

In 2026, six Chagossians tried to live on one of the islands, Île du Coin, but this is facing legal problems. There have been talks about giving control of the islands to Mauritius but keeping the military base on Diego Garcia. However, these plans are not moving forward because of concerns from the United States government.

History

Maldivian sailors knew about the Chagos Islands, calling them Fōlhavahi and Hollhavai. Sometimes traders and fishermen would get lost and arrive on these islands before being rescued. The islands were too far from Maldives to settle permanently, so they were ignored for centuries.

The islands were first charted by Vasco da Gama in the early 1500s and later claimed by France in the 1700s. They were settled by African slaves and Indian workers who built coconut plantations. In 1810, Mauritius was captured by the United Kingdom, and France gave up the islands in 1814.

The United Kingdom ended slavery in 1833, but people on the islands continued working. In 1962, a new company bought the plantations. An airstrip was built on Diego Garcia during the Second World War for military use, but the military left after the war ended.

In 1965, the United Kingdom split the Chagos Archipelago from Mauritius to create the British Indian Ocean Territory, mainly to build a military base with the United States. The local population of about 2,000 people, known as Chagossians, were moved away from the islands between 1967 and 1973 so the base could be built.

Work on the military base began in 1971, and it has been used by both the UK and US ever since. The islands of Aldabra, Farquhar, and Desroches were returned to Seychelles in 1976.

Mauritius has claimed the islands should belong to them, arguing the separation in 1965 was unfair. Legal battles over this have continued for years. In 2019, an international court said the UK should give the islands back to Mauritius, but the UK did not accept this decision.

In February 2026, four Chagossians tried to settle on one of the islands, Île du Coin, but were stopped by a court order.

Responses to transfer of BIOT

In July 2025, the British government had a legal case asking them to talk with the Chagossians before deciding what to do with their land. The court agreed to look at the case quickly, but by February 2026, the judge had not shared the decision.

In June 2025, Chagossian activists sent a legal request to the United Nations. They said the deal between the UK and Mauritius was unfair because it was made without asking the Chagossians.

In December 2025, some Chagossians set up a government in exile. After they moved back to their old town, Île du Coin, in February 2026, they changed the name.

In the House of Lords, members said the deal about the Chagos Islands was not perfect but needed to be approved. They said the government could not ignore the risk of losing the right to use the military base.

In June 2025, a group started a legal case saying the British government acted illegally when signing the agreement with Mauritius.

In February 2026, the UK Secretary of State for Defence, John Healey, was accused of giving wrong information to Parliament.

The Prime Minister of Mauritius, Navin Ramgoolam, praised the agreement. But it still needed approval from the UK Parliament.

The United States welcomed the agreement because it helps keep the joint US-UK military base at Diego Garcia working. However, in January 2026, US President Donald Trump called the agreement a mistake. In February 2026, he posted again saying the UK should not give away Diego Garcia.

The United Nations said the agreement was an important step in solving a long dispute in the Indian Ocean region.

India also welcomed the agreement.

Government

Main articles: Government of the British Indian Ocean Territory and Commissioner for the British Indian Ocean Territory

The British Indian Ocean Territory is part of the United Kingdom, and King Charles III is the head of state. There is no governor because no people live there all the time. The main leader is called the Commissioner, and Nishi Dholakia is the current one.

The laws come from a special rule book made in 2004. Since no people live there all the time, there are no elections or a local government. Most of the people there are part of the United States military, so any problems are usually handled by their military rules.

Chagossian Government

Main article: Chagossian Government

The Chagossian Government speaks for the Chagossian people of the British Indian Ocean Territory. It started in December 2025 and was called the Chagossian Government-in-Exile. In February 2026, it changed its name after its leader Misley Mandarin returned to the islands.

Naval Party 1002 and MV Grampian Frontier

Naval Party 1002 (NP 1002) is based in the British Indian Ocean Territory. It includes members from the Royal Navy and Royal Marines. Their job is to help with the territory's administration and keep things safe. They also handle customs and security tasks.

Before 2017, a ship called MV Pacific Marlin was used for patrols around the territory. In 2016, a new ship called MV Grampian Frontier started working there. This ship is 70 metres long and can carry up to 24 people. It helps with patrols, research, and conservation work. Sometimes, it works with NP 1002 members on these tasks.

Geography

Main article: Geography of the British Indian Ocean Territory

The British Indian Ocean Territory is a group of islands in the Indian Ocean. It has 58 islands that cover 56 square kilometres (22 square miles). The biggest island is Diego Garcia, which is 32.5 square kilometres (12.5 square miles) and makes up about half of the land. The other islands are much smaller. The land is flat and low, with an average height of just 1.33 metres (4.4 feet) above sea level. In 2010, a large area of ocean around the islands became a marine reserve.

The islands are:

• Diego Garcia
• Three Brothers Islands
• Egmont Islands
• Nelson Island
• Peros Banhos
• Eagle Islands
• Salomon Islands
• Danger Island

These islands are located between 4°44 and 7°41 south and 70°47 and 72°47 east.

Climate

The climate is tropical marine; hot and humid, with winds from the southeast from May to November. The average temperature is 27 °C (81 °F). Rain is common, and the islands are safe from strong storms that affect areas further south.

Transport

On Diego Garcia, there are short paved roads between the port and the airfield. Most people walk or ride bicycles. Diego Garcia's military base has the territory's only airport. The runway is long enough for big planes. There is also a big naval port. Boats can get permits to stay near the outer islands, but they must stay far away from certain protected areas. Only authorised people can go to Diego Garcia, and boats cannot come close to the island.

Unlike other British territories, BIOT drives on the right side of the road because it follows U.S. traffic rules.

Conservation

The territory is part of the International Whaling Commission's 1979 Indian Ocean Whale Sanctuary. The territory also follows rules to protect wildlife and the environment.

On 1 April 2010, a large marine protected area was created around the islands. This helps scientists study climate change and marine life, and it serves as a safe place for animals that are in danger elsewhere. Fishing is not allowed in this area.

The British Indian Ocean Territory has helped some people from the Chagossian community visit the islands and take part in scientific work. The waters around the islands are rich for fishing, but illegal fishing has been a problem. The Royal Navy has helped monitor the area to protect it.

Demographics

The British Indian Ocean Territory has special rules. People cannot live there permanently because the land is used for defense by the Government of the United Kingdom and the Government of the United States of America. Only Diego Garcia, the largest island, has people living there. Most of these people are military staff or workers, and families are not allowed to live on the island. Schools are not available there.

In 2021, a group of people from Sri Lanka, including children, ended up on Diego Garcia after their boat had problems. They were kept in a fenced area and were not allowed to leave without guards. There were concerns about their safety and treatment. In 2026, some people whose families were moved from the islands in 1971 tried to return to live there, but they were told to leave. A court stopped them from being forced away for a short time.

Economy

All economic activity happens on Diego Garcia, where joint UK/US defence facilities are located. People from Britain, Mauritius, the Philippines, and the United States work there for the military. There are no factories or farms on the islands. In the past, commercial fishing brought in money each year.

United States President Donald Trump announced a tariff on the British Indian Ocean Territory.

Services

The Navy offers places like a library, an outdoor cinema, shops, and sports centres on Diego Garcia, with prices in US dollars. The BIOT Post Office handles mail, and the territory has issued stamps since 17 January 1968. The territory does not have schools.

Telecommunications

Cable & Wireless began providing phone and internet services in 1982. In 2013, the company was bought and renamed Sure (Diego Garcia) Ltd.

Diego Garcia is close to the Equator, so it can see many geosynchronous satellites. The island has a special station that helps track satellites.

In 2022, Diego Garcia was linked to a fast underwater submarine communications cable as part of a new cable connecting Perth to Muscat. The cable also connects to Australia's Cocos Islands.

Broadcasting

The territory has three FM radio stations run by the American Forces Network and British Forces Broadcasting Service. People can also use amateur radio from Diego Garcia.

.io domain name

The .io country-code top-level domain was given to a British entrepreneur in 1997. He sold it in 2017 for US$70 million.

Sports

The Chagos Islands national football team was formed by people from the islands. They have played in non-FIFA competitions, like the 2016 CONIFA World Football Cup.