Early history and ethnogenesis In 1793, when the first successful colony was founded on Diego Garcia,
coconut plantations were established on many of the atolls and isolated islands of the archipelago. Initially the workers were enslaved Africans, but after 1840 they were freemen, many of whom were descended from those earlier enslaved. They formed an inter-island culture called
Ilois (a
French Creole word meaning Islanders).
Expulsion and dispossession In 1965, as part of a deal to grant Mauritian independence, the UK separated the
Chagos Archipelago, at the time a part of its
Mauritius territory, from the colony and reorganized it as the
British Indian Ocean Territory. The UK also labelled the Chagossians, whose ancestral links to the territory go back to the late 18th century, as “transient workers” to avoid breaching International Law. On 16 April 1971, the United Kingdom issued a policy called BIOT Immigration Ordinance #1 which made it a criminal offence for those without military clearance to be on the islands without a permit. Between 1967 and 1973, the Chagossians, then numbering over 1,000 people, were
expelled by the British government, first to the island of
Peros Banhos, away from their homeland, and then, in 1973, to Mauritius. A number of Chagossians who were evicted reported that they were threatened with being shot or bombed if they did not leave the island. In early April 2006, in an excursion organised and financed by the British Foreign and Commonwealth Office, a group of around a hundred Chagossians were permitted to visit the
British Indian Ocean Territory for the first time in over thirty years.
Court battles In April 2006, the
United States Court of Appeals for the District of Columbia Circuit rejected a lawsuit by
Louis Olivier Bancoult and other Chagossians, finding that their claims were a non-justiciable
political question, i.e. a question that U.S. courts cannot handle because it is properly the business of the Congress to address it legislatively. On 11 May 2006, the Chagossians won their case in the
High Court of Justice in England, which found that they were entitled to return to the Chagos Archipelago. It remained to be seen how this judgment might be implemented in practice. However, in June 2006 the British government filed an appeal in the Court of Appeal against the High Court's decision. The
Foreign and Commonwealth Office put forward an argument based on the
treatment of the Japanese Canadians following the attacks on Pearl Harbor. After the Court of Appeal had upheld the decision of the High Court, the British government appealed successfully to the
Judicial Committee of the House of Lords. On 22 October 2008, the
Law Lords reached a
decision on the appeal made by the
Secretary of State for Foreign and Commonwealth Affairs,
David Miliband. They found in favour of the Government in a 3–2 verdict, ending the legal process in the UK and dashing the islanders' hopes of return. The judges who voted to allow the government's appeal were
Lord Hoffmann,
Lord Rodger of Earlsferry, and
Lord Carswell; those dissenting were
Lord Bingham of Cornhill and
Lord Mance. In 2016, the British government denied the right of the Chagossians to return to the islands after a 45-year legal dispute. In 2019, the
International Court of Justice issued an advisory opinion stating that the United Kingdom did not have sovereignty over the Chagos Islands and that the administration of the archipelago should be handed over "as rapidly as possible" to Mauritius.
Marine nature reserve and government communications leak In April 2010, the British Government—specifically, the British diplomat
Colin Roberts, acting on the instructions of
David Miliband—established a marine nature reserve around the Chagos Islands known as the
Chagos Marine Protected Area. The designation proved controversial as the decision was announced during a period when the
UK Parliament was in recess. On 1 December 2010, a leaked
US Embassy London diplomatic cable dating back to 2009 exposed British and US calculations in creating the marine nature reserve. The cable relays exchanges between US Political Counselor Richard Mills and British Director of the Foreign and Commonwealth Office Colin Roberts, in which Roberts "asserted that establishing a marine park would, in effect,
put paid to resettlement claims of the archipelago's former residents". Richard Mills concludes: However, the cable also mentions that "there are proposals (for a marine park) that could provide the Chagossians warden jobs". As of 2018, no such jobs exist. The cable (reference ID "09LONDON1156") was
classified as
confidential and "
no foreigners", and leaked as part of the
Cablegate cache. Armed with the
WikiLeaks revelations, the Chagossians launched an appeal, seeking a judgement that the reserve was unlawfully aimed at preventing them from returning home. Although
United States Army soldier
Chelsea Manning had been arrested nearly three years previously for the leaks, the UK government felt unable to confirm to the court that the leaked documents were genuine. It was made clear to the court that the government's inability to confirm was for two reasons: firstly, to protect itself from the charge that it created the reserve to prevent the islanders from ever returning home and, secondly, out of a purported fear that the US government might get angry if the cables were acknowledged as genuine. In June 2013, the pair of judges turned down the appeal brought by the Chagossians, ruling that the reserve was compatible with EU law. In response to the revelations, the chair of the Chagos Refugees Group UK Branch,
Sabrina Jean, noted:
Discourse about the Chagossians from
Patrick Wright, Baron Wright of Richmond signed by
D. A. Greenhill, dated August 24, 1966, stating "Unfortunately along with the Birds go some few
Tarzans or
Men Fridays." The
WikiLeaks cables revealed diplomatic cables between the US and UK about the Chagossians. A cable written by
D.A. Greenhill on 24 August 1966 to a US State Department official refers to the Chagossians as "some few
Tarzans or
Man Fridays". Similar language appears in a 2009 US State Department cable (09LONDON1156), which offered a description of the UK government's views about the effect of the Marine Protection Act:
2012 petition On 5 March 2012, a petition was launched on
We the People section of the
whitehouse.gov website in order to ask the
White House in the United States to consider the Chagos case. The petition read as follows: On 4 April 2012, the sufficient number of 25,000 signatures was met to require a response from the
Office of the President under its policy. An undated response was posted on the White House petition web site by the
United States Department of State, in the name of
Michael Posner (
Assistant Secretary of State for Democracy, Human Rights, and Labor),
Philip H. Gordon (
Assistant Secretary of State for European and Eurasian Affairs) and
Andrew J. Shapiro (
Assistant Secretary of State for Political-Military Affairs). The response read as follows:
Possible return following the 2024 handover agreement A Chagossian resettlement plan, overseen by international experts, will be discussed in June 2025. In June 2025, the Great British PAC, with militant of right of chagossien launched a legal action aimed at demonstrating the illegal actions of the British government in signing this restitution agreement. The agreement may be renewed for an additional 40 years after the initial 99-year period, and for an additional period thereafter. On June 10, 2025, UN experts called for the suspension of a recently signed agreement between the United Kingdom and Mauritius, warning that it failed to protect the rights of the displaced Chagossian people. “By maintaining a foreign military presence of the United Kingdom and the United States on Diego Garcia and preventing the Chagossian people from returning… the agreement appears to be in contradiction with the Chagossian right of return,” according to the experts. The experts criticized the lack of provisions allowing access to cultural sites or the preservation of the Chagossian heritage. They called on the two countries to renegotiate the restitution agreement, stating, “We call for the suspension of ratification of the agreement and the negotiation of a new agreement that fully guarantees the rights of the Chagossian people”. The British House of Lords is considering a motion arguing against ratification of the treaty on June 30, 2025. In July 2025, a legal action demanding that the British government consult with the Chagossians before transferring sovereignty of their territory progressed before the High Court. The judicial review, initiated by Chagossian claimant Louis Misley Mandarin with the support of the Great British PAC, was accepted and fast-tracked by the High Court, with a decision set for July 2025.
2026 return , used by the self-declared
Chagossian Government In February 2026, a group of four Chagossians returned to
Île du Coin to
reestablish a permanent settlement, without seeking government permission. The group's leader,
Misley Mandarin, leads the self-declared
Chagossian Government which claims to represent the interests of the Chagossian people and which supports the continuation of British sovereignty. == Indigenous status ==