View source for Chagos Archipelago

{{short description|Archipelago in the Indian Ocean}}
{{About|the geopolitical region|the British territory located within the region|British Indian Ocean Territory}}
{{Use dmy dates|date=May 2025}}
{{Infobox islands
| disputed           = 
| name               = Chagos Archipelago
| plural             = yes
| image_name         = Chagos map2y.PNG
| image_size         = 250px
| image_caption      = Map of the Chagos Archipelago
| image_map          = {{Location map |Indian Ocean
 |lon_dir = E
 |lat_dir = S
 |lat_deg = 5
 |lat_min = 20
 |lon_deg = 71
 |lon_min = 51
 |float = center
 |width = 250
 |mark = Location circle.svg
 |marksize = 20
 |caption = 
}}
| map_caption        = Location of the Chagos Archipelago (circled)
| location           = [[Indian Ocean]]
| coordinates        = {{Coord|6|00|S|71|30|E|display=inline,title}}
| major_islands      = [[Diego Garcia]], [[Peros Banhos]], [[Salomon Islands]], [[Egmont Islands]]
| area_km2           = 56.13
| country                    = {{flag|United Kingdom}}
| country_admin_divisions_title = Territory
| country_admin_divisions    = [[British Indian Ocean Territory]]
| country1                   = {{flag|Mauritius}}
| country1_admin_divisions_title = [[Outer Islands of Mauritius|Outer Islands]]
| country1_admin_divisions   = Chagos Archipelago
| demonym                    = [[Chagossians|Chagossian<br/>Chagos Islander]] <br/> {{lang|fr|Îlois|italic=no}}
| population         = 4,267 ([[Diego Garcia|Eclipse Point Town]])
| population_as_of   = 2020
| ethnic_groups      = {{unbulleted list|{{nowrap|95.88% [[British people|British]]{{\}}[[Americans|American]]}} |4.12% others|(native population [[exile]]d)}}
}}
The '''Chagos Archipelago''' ({{IPAc-en|ˈ|tʃ|ɑː|ɡ|ə|s|,_|-|ɡ|ə|s}}) or '''Chagos Islands''' (formerly {{lang |pt |Bassas de Chagas}},<ref>{{cite web |url=http://catalogue.nla.gov.au/Record/3665462 |title=Track of the Calcutta East Indiaman, over the Bassas de Chagas in the Indian Ocean |website=Catalogue.nla.gov.au |access-date=2012-06-21 |archive-date=2 January 2014 |archive-url=https://web.archive.org/web/20140102192012/http://catalogue.nla.gov.au/Record/3665462 |url-status=live }}</ref> and later the '''Oil Islands''') is a group of seven [[atoll]]s comprising more than 60 islands in the [[Indian Ocean]] about {{convert|500|km}} south of the [[Maldives]] archipelago. This chain of islands is the southernmost [[archipelago]] of the [[Chagos–Laccadive Ridge]], a long [[submarine mountain range]] in the [[Indian Ocean]].<ref>{{NatGeo ecoregion|id=im0125|name=Maldives-Lakshadweep-Chagos Archipelago tropical moist forests|access-date=2012-06-21}}</ref> In its north are the [[Salomon Islands]], [[Nelsons Island]] and [[Peros Banhos]]; towards its south-west are the [[Three Brothers, Chagos|Three Brothers]], [[Eagle Islands]], [[Egmont Islands]] and [[Danger Island, Great Chagos Bank|Danger Island]]; southeast of these is [[Diego Garcia]], by far the largest island. All are low-lying atolls, save for a few extremely small instances, set around [[lagoon]]s.

From 1715 to 1810, the Chagos Islands were part of France's [[List of French possessions and colonies|Indian Ocean possessions]], administered through [[Isle de France (Mauritius)|Isle de France]]{{snd}}which was a [[French colonial empire|colony of France]] (later renamed as [[Mauritius]]). Under the [[Treaty of Paris (1814)|Treaty of Paris]] in 1814, France ceded {{lang |fr |Isle de France}} and the Chagos Islands to the [[United Kingdom]].<ref name="real" /><ref>{{cite news|url=https://www.reuters.com/article/us-britain-chagos-un-idUSKBN19D2LW?il=0|title=U.N. asks international court to advise on Chagos; Britain opposed|last1=Nichols|first1=Michelle|date=22 June 2017|access-date=23 June 2017|work=Reuters|archive-date=18 October 2017|archive-url=https://web.archive.org/web/20171018013124/https://www.reuters.com/article/us-britain-chagos-un-idUSKBN19D2LW?il=0|url-status=live}}</ref>

In 1965, the United Kingdom split its administration of the Chagos Archipelago away from Mauritius and into the [[British Indian Ocean Territory]] (BIOT). The islands were formally established as an overseas territory of the United Kingdom on 8 November 1965.<ref name="Annex 29PCA">{{Cite web |date=8 November 1965 |title=ANNEX 29 - Colonial Office Telegram No. 298 to Mauritius, 8 November 1965,FO 371/184529 |url=https://files.pca-cpa.org//pcadocs/mu-uk/Annexes%20to%20Memorial/MM%20Annexes%201-80.pdf |access-date=26 February 2025 |publisher=[[Permanent Court of Arbitration]]}}</ref> 

The Chagos Islands had been home to the [[Chagossians]], a [[Bourbonnais Creole]]–speaking people, until the United Kingdom [[Expulsion of the Chagossians|expelled them from the archipelago]] at the request of the [[United States]] between 1967 and 1973 to allow the United States to build [[Naval Support Facility Diego Garcia]], which operates under a special agreement allowing significant US military presence. The main forcible removal of Diego Garcia’s population took place in July and September 1971.<ref name="ICJ Summary">{{Cite web |date=25 February 2019 |title=Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965 Summary of the Advisory Opinion |url=https://www.icj-cij.org/sites/default/files/case-related/169/169-20190225-SUM-01-00-EN.pdf |access-date=26 February 2025 |publisher=[[International Court of Justice]]}}</ref> Since 1971 only the atoll of Diego Garcia has been inhabited, and only by employees of the military including civilian contracted personnel. Since being expelled, Chagossians have been prevented from entering the islands. 

Mauritius was engaged in a [[Chagos Archipelago sovereignty dispute|sovereignty dispute]] with the UK, claiming the Chagos Archipelago as part of Mauritius. The [[International Court of Justice]] (ICJ) and the [[International Tribunal for the Law of the Sea]] both stated that the UK had an obligation to return the islands to Mauritius.<ref>{{cite web|title=Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965|url=https://www.icj-cij.org/en/case/169|publisher=International Court of Justice|access-date=11 May 2019|archive-date=24 May 2019|archive-url=https://web.archive.org/web/20190524050858/https://www.icj-cij.org/en/case/169|url-status=live}}</ref><ref name="un court">{{Cite news|date=2021-01-28|title=UN court rules UK has no sovereignty over Chagos islands|language=en-GB|work=BBC News|url=https://www.bbc.com/news/world-africa-55848126|access-date=2021-07-18|archive-date=28 January 2021|archive-url=https://web.archive.org/web/20210128183430/https://www.bbc.com/news/world-africa-55848126|url-status=live}}</ref><ref>{{Cite news|date=2021-05-16|title=UN favours Mauritian control of Chagos Islands by rejecting UK stamps|url=http://www.theguardian.com/world/2021/may/16/un-favours-mauritian-control-over-chagos-islands-by-rejecting-uk-stamps|access-date=2021-07-18|first=Haroon |last=Siddique|newspaper=[[The Guardian]]|language=en}}</ref> In October 2024, the British government announced it would transfer the Chagos Islands to Mauritius subject to finalisation of a treaty.<ref>{{Cite web |url=https://www.bbc.co.uk/news/articles/c98ynejg4l5o |title=UK will give sovereignty of Chagos Islands to Mauritius |date=3 October 2024 |website=BBC News |publisher=BBC |access-date=3 October 2024 |last1=Harding |first1=Andrew |archive-date=3 October 2024 |archive-url=https://web.archive.org/web/20241003225136/https://www.bbc.co.uk/news/articles/c98ynejg4l5o |url-status=live }}</ref> The transfer agreement was signed on 22 May 2025, with the provision that the island of Diego Garcia would be leased back to the UK for at least 99 years.<ref>{{cite web|title=UK signs deal to hand Chagos Islands to Mauritius |url=https://www.aljazeera.com/news/2025/5/22/uk-court-temporarily-blocks-deal-to-hand-chagos-islands-to-mauritius |website=Al Jazeera |access-date=22 May 2025}}</ref> The UK government {{update after |2025 |text=expects the treaty to be ratified near the end of 2025.}}<ref name=":1">{{cite web |date=30 May 2025 |title=2025 treaty on the British Indian Ocean Territory/Chagos Archipelago |url=https://commonslibrary.parliament.uk/research-briefings/cbp-10273/ |website=Parliament of the United Kingdom}}</ref>

==Geography==
{{More citations needed section|date=July 2021}}
[[File:Chagos large.png|thumb|The Chagos Archipelago.<br/>[[Atoll]]s with areas of dry land are named in green.]]
The archipelago is about {{convert|500|km|mi}} south of the [[Maldives]], {{convert|1880|km|mi}} east of the [[Seychelles]], {{convert|1680|km|mi}} north-east of [[Rodrigues|Rodrigues Island]] ([[Mauritius]]), {{convert|2700|km|mi}} west of the [[Cocos (Keeling) Islands]], and {{convert|3400|km|mi}} north of [[Île Amsterdam|Amsterdam Island]].

The land area of the islands is {{cvt|56.1|km2}}, the largest island, Diego Garcia, having an area of {{cvt|32.5|km2}}. The total area, including lagoons within atolls, is more than {{cvt|15000|km2}}, of which {{cvt|12642|km2}} are accounted by the [[Great Chagos Bank]], the largest acknowledged atoll structure of the world (the completely submerged [[Saya de Malha Bank]] is larger, but its status as an atoll is uncertain). The [[Continental shelf|shelf]] area is {{cvt|20607|km2}}, and the [[Exclusive Economic Zone]], which borders the corresponding zone of the Maldives in the north, has an area of {{cvt|639|km2}} (including [[territorial waters]]).

The Chagos group is a combination of different [[coralline rock]] structures topping a [[Chagos-Laccadive Ridge|submarine ridge]] running southwards across the centre of the Indian Ocean, formed by volcanoes above the [[Réunion hotspot]]. Unlike the Maldives, there is no clearly discernible pattern in the atoll arrangement, which makes the whole archipelago look somewhat chaotic. Most of the coralline structures of the Chagos are submerged reefs.

The Chagos contain the world's largest coral atoll, The Great Chagos Bank, which supports half the total area of good quality reefs in the Indian Ocean. As a result, the ecosystems of the Chagos have so far proven resilient to [[climate change]] and environmental disruptions.

The largest individual islands are Diego Garcia ({{cvt|32.5|km2|disp=or}}), Eagle (Great Chagos Bank, {{cvt|3.1|km2|disp=or}}), {{lang |fr |Île Pierre}} (Peros Banhos, {{cvt|1.4|km2|disp=or}}), Eastern Egmont (Egmont Islands, {{cvt|2.175|km2|disp=or}}), {{lang |fr |Île du Coin}} (Peros Banhos, {{cvt|1.32|km2|disp=or}}) and {{lang |fr |Île Boddam}} (Salomon Islands, {{cvt|1.27|km2|disp=or}}).

In addition to the seven atolls with dry land reaching at least the high-water mark, there are nine reefs and [[bank (topography)|banks]], most of which can be considered permanently submerged atoll structures. The number of atolls in the Chagos Archipelago is given as four or five in most sources, plus two island groups and two single islands, mainly because it is not recognised that the Great Chagos Bank is a huge atoll structure (including those two island groups and two single islands), and because [[Blenheim Reef]], which has islets or cays above or just reaching the high-water mark, is not included. Features are listed in the table from north to south:
{{GeoGroup|section=Mountains and peaks}}<br />
{| class="wikitable"
|-
! rowspan=2 | !! rowspan=2 | Atoll/Reef/Bank <br/>(''alternate name'') !! rowspan=2 | type !! colspan=2 | Area (km<sup>2</sup>) !! rowspan=2 | number <br/> of islands !! rowspan=2 | [[Geographic coordinate system|Location]]
|-
! Land !! Total
|- style="background: #ccf"
| align=right | 0 || unnamed bank || submerged bank || align=right |– || align=right | 3 || align=right |– || {{Coord|04|25|S|72|36|E}}
|- style="background: #cff"
| align=right | 1 || [[Colvocoresses Reef]] || submerged atoll || align=right |– || align=right | 10 || align=right |– || {{Coord|04|54|S|72|37|E|name=Colvocoresses Reef}}
|- style="background: #FFC;"
| align=right | 2 || [[Speakers Bank]] || unvegetated atoll || align=right | 0.001 || align=right | 582 || align=right | <sup>1)</sup> || {{Coord|04|55|S|72|20|E|name=Speakers Bank}}
|- style="background: #FFC;"
| align=right | 3 || [[Blenheim Reef]] (''Baixo Predassa'') || unvegetated atoll || align=right | 0.02 || align=right | 37 || align=right | 4 || {{Coord|05|12|S|72|28|E|name=Blenheim Reef}}
|- style="background: #CFF;"
| align=right | 4 || [[Benares Shoals]] || submerged reef || align=right |– || align=right | 2 || align=right | || {{Coord|05|15|S|71|40|E|name=Benares Shoals}}
|- style="background: #CFC;"
| align=right | 5 || [[Peros Banhos]] || atoll || align=right | 9.6 || align=right | 503 || align=right | 32 || {{Coord|05|20|S|71|51|E|name=Peros Banhos}}
|- style="background: #CFC;"
| align=right | 6 || [[Salomon Islands]] || atoll || align=right | 3.56 || td style="text-align:right;"| 36 || align=right | 11 || {{Coord|05|22|S|72|13|E|name=Salomon Islands}}
|- style="background: #CFF;"
| align=right | 7 || [[Victory Bank]] || submerged atoll || align=right |– || align=right | 21 || align=right |– || {{Coord|05|32|S|72|14|E|name=Victory Bank}}
|- style="background: #CFC;"
| align=right | 8a || [[Nelsons Island|Nelson Island]] || rowspan="4"|parts of mega-atoll <br/> [[Great Chagos Bank]] || align=right | 0.61 || style="text-align:right;" rowspan="4"|12642 || align=right | 1 || {{Coord|05|40|53|S|72|18|39|E|name=Nelson Island}}
|- style="background: #CFC;"
| align=right | 8b || [[Three Brothers, Chagos|Three Brothers]] (''Trois Frères'') || align=right | 0.53 || align=right | 3 || {{Coord|06|09|S|71|31|E|name=Three Brothers}}
|- style="background: #CFC;"
| align=right | 8c || [[Eagle Islands]] || td style="text-align:right;"| 3.43 || align=right | 2 || {{Coord|06|12|S|71|19|E|name=Eagle Islands}}
|- style="background: #CFC;"
| align=right | 8d || [[Danger Island, Great Chagos Bank|Danger Island]] || align=right | 1.06 || align=right | 1 || {{Coord|06|23|00|S|71|14|20|E|name=Danger Island|region:GB_type:isle}}
|- style="background: #CFC;"
| align=right | 9 || [[Egmont Islands]] || atoll || align=right | 4.52 || align=right | 29 || align=right | 7 || {{Coord|6|40|S|71|21|E|type:isle|name=Egmont Islands}}
|- style="background: #CFF;"
| align=right | 10 || [[Cauvin Bank]] || submerged atoll || align=right |– || align=right | 12 || align=right |– || {{Coord|06|46|S|72|22|E|name=Cauvin Bank}}
|- style="background: #CCF;"
| align=right | 11 || [[Owen Bank]] || submerged bank || align=right |– || align=right | 4 || align=right |– || {{Coord|06|48|S|70|14|E|name=Owen Bank}}
|- style="background: #CFF;"
| align=right | 12 || [[Pitt Bank]] || submerged atoll || align=right |– || align=right | 1317 || align=right |– || {{Coord|07|04|S|71|21|E|name=Pitt Bank}}
|- style="background: #CFC;"
| align=right | 13 || [[Diego Garcia]] || atoll || align=right | 32.8 || align=right | 174 || align=right | 4<sup>2)</sup> || {{Coord|07|19|S|72|25|E|name=Diego Garcia}}
|- style="background: #CFF;"
| align=right | 14 || [[Ganges Bank]] || rowspan=3 | submerged atoll || style="text-align:right;" rowspan="3"|– || align=right | 30 || style="text-align:right;" rowspan="3"|– || {{Coord|07|23|S|70|58|E|name=Ganges Bank}}
|- style="background: #CFF;"
| align=right | 15 || [[Wight Bank]] || align=right | 3 || {{Coord|07|25|S|71|31|E|name=Wight Bank}}
|- style="background: #CFF;"
| align=right | 16 || [[Centurion Bank]] || align=right | 25 || {{Coord|07|39|S|70|50|E|name =Centurion Bank}}
|- style="background: #DDD;"
| align=right | || '''Chagos Archipelago''' || Archipelago || align=right | 56.13 || align=right | 15427 || align=right | 64 || 04°54' to 07°39'S <br/>70°14' to 72°37' E
|-
| colspan="9" style="background:#eee;"| <sup>1)</sup> a number of drying sand cays
|-
| colspan="9" style="background:#eee;"| <sup>2)</sup> main island and three islets at the northern end
|}

===Resources===
[[File:Salomons Atoll in the Chagos.jpg|thumb|[[Salomon Atoll]] is one of the many above water features of the Chagos Archipelago.]]
[[File:Chagos 022.jpg|thumb|The Chagos Archipelago is a hotspot of [[biodiversity]] in the Indian Ocean.]]
The main [[natural resources]] of the area are [[coconut]]s and fish. The licensing of [[Fishing industry|commercial fishing]] used to provide an annual income of about {{USD|2{{nbsp}}million}}{{as of? |date=May 2025}} for the British Indian Ocean Territory authorities. However, licenses have not been given since October 2010; the last expired after the creation of the no-take marine reserve.<ref>{{cite Hansard |url=https://publications.parliament.uk/pa/cm200304/cmhansrd/vo040621/text/40621w13.htm#40621w13.html_sbhd2 |title=British Indian Ocean Territories |at=Foreign and Commonwealth Affairs |jurisdiction=Parliament of the United Kingdom |house=House of Commons |date=21 June 2004 |column=1219W |hansard=Bound Volume Hansard - Written Answers |position=Parliamentary Under-Secretary (Foreign and Commonwealth Office) |speaker=[[Jeremy Corbyn]], [[Bill Rammell]]|access-date=2013-10-20 |archive-date=13 May 2006 |archive-url=https://web.archive.org/web/20060513034414/http://www.publications.parliament.uk/pa/cm200304/cmhansrd/vo040621/text/40621w13.htm#40621w13.html_sbhd2 |url-status=live }}</ref>

All economic activity is concentrated on the largest island of Diego Garcia, where joint UK–US military facilities are located. Construction projects and various services needed to support the military installations are done by military and contract employees from the UK, Mauritius, the [[Philippines]], and the US. There are currently no industrial or agricultural activities on the islands. All the water, food and other essentials of daily life are shipped to the island. An independent feasibility study led to the conclusion that resettlement would be "costly and precarious".{{quote without source |date=May 2025}} Another feasibility study, commissioned by organisations supporting resettlement, found that resettlement would be possible at a cost to the British taxpayer of {{GBP|25{{nbsp}}million|link=yes}}.{{as of? |date=May 2025}}{{fact |date=May 2025}} If the Chagossians return, they plan to re-establish [[copra]] production and fishing, and to begin the commercial development of the islands for tourism.

Until October 2010, [[Skipjack tuna|Skipjack]] (''Euthynnus pelamis'') and [[yellowfin tuna]] (''Thunnus albacares'') were fished for about two months of the year as their year-long migratory route takes them through Chagos waters. While the remoteness of the Chagos offers some protection from extractive activities, legal and illegal fishing have had an impact. There is considerable [[poaching]] of turtles and other marine life. Sharks, which play a vital role in balancing the food web of tropical reefs, have suffered sharp declines from [[illegal fishing]] for their fins and as [[bycatch]] in legal fisheries. [[Sea cucumber]]s, which cleanse sand, are poached to feed Asian markets.

===Climate===
The Chagos Archipelago has a [[Tropical climate|tropical]] [[oceanic climate]]; hot and [[humid]] but moderated by [[trade winds]].
Climate is characterised by plenty of sunshine, warm temperatures, showers and light breezes.
December through February is considered the rainy season (summer monsoon); typical weather conditions include light west-northwesterly winds and warmer temperatures with more rainfall. June to September is considered the drier season (winter), characterised by moderate south-easterly winds, slightly cooler temperatures and less [[rainfall]]. The annual mean rainfall is {{convert|2600|mm}}, varying from {{convert|105|mm}} during August to {{convert|350|mm}} during January.

==History==
[[File:Nazareth Bank-1794 Samuel Dunn Wall Map of the World in Hemispheres - Geographicus - World2-dunn-1794.jpg|thumb|upright=1.5|The Chagos as ''Bassas de Chagas'' at the top right corner on a 1794 map by [[Samuel Dunn (mathematician)|Samuel Dunn]]]]

===Early history===
According to Southern [[Maldivians|Maldivian]] [[oral tradition]], local traders and fishermen were occasionally lost at sea and became stranded in one of the islands of the Chagos. Eventually they were rescued and brought back home.<ref name="NIAS Press">[[Xavier Romero-Frias|Romero-Frias, Xavier]] (2012). ''Folk tales of the Maldives'', NIAS Press, {{ISBN|978-87-7694-104-8}}, {{ISBN|978-87-7694-105-5}}.</ref> However, these islands were judged to be too far away from the Maldives to be settled permanently by [[Maldivians]]. Thus, for many centuries, the Chagos were ignored by their northern neighbours. However, these tales contrast with the historical view that the Maldives has towards the Chagos, as they were considered to be an extension of Maldivian maritime territory. For centuries, the Maldivians have used the Chagos as a base for fishing expeditions. People would camp on the islands, catch fish, and cook, smoke, and dry them.{{citation needed|date=April 2025}} Additionally, the exiled Maldive King Hassan IX (also known as Dom Manoel), while in [[Kochi|Cochin]], describes himself in his letters patent of 1561 as King of the Maldive islands, including seven of the islands of Pullobay, referring to ''Fōlhavahi'' or the Chagos, and this letter survives in a Portuguese archive in Lisbon.<ref>{{Cite news |last=Nasheed |first=Mohamed |date=2024-10-10 |title=The U.K. and 'leaving lessons' from the Indian Ocean |url=https://www.thehindu.com/opinion/op-ed/the-uk-and-leaving-lessons-from-the-indian-ocean/article68741970.ece |access-date=2024-10-12 |work=The Hindu |language=en-IN |issn=0971-751X}}</ref><ref name="Pyrard of Laval">{{Cite book |last1=Pyrard |first1=François |title=The voyage of François Pyrard of Laval to the East Indies, the Maldives, the Moluccas, and Brazil: translated into English from the third French edition of 1619. Vol. 1 |last2=Gray |first2=Albert |last3=Bell |first3=Harry Charles Purvis |date=2010 |publisher=Ashgate |isbn=978-1-4094-1582-4 |edition=Reprint d. Ausg. London, Hakluyt Soc., 1887 |series=Works issued by the Hakluyt Society |volume=1 |location=Farnham}}</ref>

In Maldivian lore the whole group is known as ''Fōlhavahi'' or ''Hollhavai'' ({{Langx|dv|ފޯޅަވަހި or ހޮއްޅަވައި}}) (the latter name in the Southern Maldives [[Addu Atoll|Adduan]] dialect of [[Dhivehi language|Dhivehi]]). There are no separate names for the different atolls of the Chagos in the Maldivian oral tradition; ''Fayhandheeb'' is used for the Archipelago as a whole. According to Maldivian history, the Maldives Archipelago consists of Mahaldheeb, Suvaadheebu and Feyhandheeb.<ref>Romero-Frias, Xavier, ''The Maldive Islanders, A Study of the Popular Culture of an Ancient Ocean Kingdom.'' Barcelona, 1999, {{ISBN|84-7254-801-5}}. Chapter 1 "A Seafaring Nation", p. 19.</ref>

===16th to 19th century===
[[File:Admiralty Chart No 3 Chagos Archipelago, Published 1839, Large Corrections 1906.jpg|thumb|Nautical chart of the Chagos Archipelago from Moresby's survey of 1837]]
The first Europeans to become aware of the archipelago were [[Portuguese Discoveries|Portuguese explorers]]. Although the Portuguese navigator [[Pedro Mascarenhas|Pedro de Mascarenhas]] (1470 – 23 June 1555) is credited with having encountered the islands during his voyage of 1512–13, there is little corroborative evidence; cartographic analysis points to 1532 or later.{{Citation needed|date=August 2018}} [[Portugal in the Age of Discovery|Portuguese]] seafarers named the group {{lang |pt |Bassas de Chagas}},<ref>Huddart, Joseph, et al. ''The oriental navigator, or, New directions for sailing to and from the East Indies'', {{ISBN|978-0-699-11218-5}}.</ref> {{lang|pt|Chagas}} ({{lit |wounds}}) referring to the [[Holy Wounds]] of the [[crucifixion of Jesus]]. They also named some of the atolls, such as Diego Garcia and [[Peros Banhos]] Atoll, mentioned as ''Pedro dos Banhos'' in 1513 by [[Afonso de Albuquerque]].<ref>[[John Purdy (hydrographer)|Purdy, John]], ''Memoir, descriptive explanatory, accompany new chart Ethiopic or southern Atlantic Ocean, western coasts South-America, Cape Horn Panama'', {{ISBN|1-141-62555-5}}.</ref> This lonely and isolated group, economically and politically uninteresting to the Portuguese, was never made part of the [[Portuguese Empire]].<ref>Boxer, C R., ''The Portuguese Seaborne Empire, 1415–1825'', Knopf, 1969, {{ISBN|978-0-09-097940-0}}.</ref>

The earliest and most interesting description of the Chagos, before coconut trees grew widely on the islands, was written by Manoel Rangel, a castaway from the Portuguese ship ''Conceição'' which ran aground on the Peros Banhos reefs in 1556.<ref>Bernardo Gomes de Brito. ''[[História trágico-marítima]]. Em que se escrevem chronologicamente os Naufragios que tiverao as Naos de Portugal, depois que se poz em exercicio a Navegaçao da India.'' Lisboa 1735</ref>

The oldest known written document claiming the Chagos is attributed to King Hassan IX of the Maldives in the year 1561.<ref name="Pyrard of Laval" /> The [[Kingdom of France|French]] were the first European colonial power to lay claim to the Chagos after they settled {{lang |fr |Île Bourbon}} (now [[Réunion]], in 1665) and [[Isle de France (Mauritius)|Isle de France]] (now Mauritius, in 1715). The French began issuing permits for companies to establish coconut oil plantations on the Chagos in the 1770s.<ref>{{cite web|title=US-UK-Diego Garcia (1770–2004)|url=http://www.historycommons.org/timeline.jsp?timeline=diego_garcia|website=History Commons|access-date=17 July 2014|archive-url=https://web.archive.org/web/20101230022139/http://www.historycommons.org/timeline.jsp?timeline=diego_garcia|archive-date=30 December 2010|url-status=dead}}</ref> 

On 27 April 1786 the Chagos Islands and Diego Garcia were claimed for [[Kingdom of Great Britain|Great Britain]]. However, the territory was ceded to [[United Kingdom of Great Britain and Ireland|Britain]] by treaty only after [[Napoleon]]'s defeat, in 1815. The Chagos were governed from Mauritius, which was by that time also a British colony.<ref>{{cite journal|author1=Christian Nauvel|title=A Return from Exile in Sight? The Chagossians and Their Struggle|journal=Northwestern Journal of International Human Rights|date=2007|volume=5|issue=1|page=6|url=http://www.law.northwestern.edu/journals/jihr/v5/n1/4/Nauvel.pdf|access-date=17 July 2014|archive-date=2 March 2011|archive-url=https://web.archive.org/web/20110302222704/http://www.law.northwestern.edu/journals/jihr/v5/n1/4/Nauvel.pdf|url-status=dead}}</ref>

In 1793, when the first successful colony was founded on Diego Garcia, the largest island, [[coconut]] [[plantation]]s were established on many of the atolls and isolated islands of the archipelago. The workers were enslaved by the British and not freed until 1840, after which time many of the workers descended from those who had earlier been enslaved. They formed an inter-island culture called ''[[Ilois]]'', a [[French-based creole languages|French Creole]] word meaning {{gloss |islanders}}.

Commander [[Robert Moresby]] made a survey of the Chagos on behalf of the [[British Admiralty]] in 1837–1838. After Moresby had taken measurements of most of the atolls and reefs, the archipelago was charted with relative precision for the first time.<ref>[[British Hydrographic Services]]. Admiralty Charts. Maps in the Chagos Archipelago.</ref>

'''Moresby's survey''' 

[[Robert Moresby]] was a captain of the [[East India Company]]'s Bombay Marine/Indian Navy who distinguished himself as a hydrographer, maritime surveyor and draughtsman.

After his completion of the Red Sea Survey, Moresby was sent to chart various coral island groups lying across the track of India-to-Cape trade. In 1834–36 Moresby, assisted by Lieutenants Christopher and Young, undertook the difficult cartography of the Maldive Islands, drawing the first accurate maritime charts of this complicated Indian Ocean atoll group (Admiralty Charts). These charts were printed as three separate large maps by the Hydrographic Service of the Royal Navy.

Moresby's survey of the Atolls of the Maldives was followed by the Chagos Archipelago. where he conducted "a thorough scientific survey".{{quote without source |date=May 2025}} He planted 30 [[breadfruit]] trees in Diego Garcia Island, the largest of the group. Moresby reported that "there were cats and chickens on the island".{{citation needed|date=April 2025}}

===20th century===
[[File:Diplomatic Cable signed by D.A. Greenhill, dated August 24, 1966.jpg|thumb|[[Diplomatic cable]] signed by [[Denis Greenhill, Baron Greenhill of Harrow|D.{{nbsp}}A. Greenhill]], 1966, relating to the [[Depopulation of Chagossians from the Chagos Archipelago|depopulation of the Chagos Archipelago]] stating "Unfortunately along with the birds go some few [[Tarzan]]s or [[Friday (Robinson Crusoe)|Men Friday]]s whose origins are obscure and who are being hopefully wisked on to Mauritius etc. When this has been done I agree we must be very tough"]]
[[File:Église Boddam.JPG|thumb|left|Abandoned church on Boddam Island, [[Salomon Atoll]]]]
On 31 August 1903 the Chagos Archipelago was administratively separated from the [[Seychelles]] and attached to Mauritius.<ref>{{cite book|title=A New Comprehensive History of Mauritius Vol 1|url=https://books.google.com/books?id=r2_aqwyx99EC&pg=PA398|publisher=Sydney Selvon|isbn=978-99949-34-94-2|pages=398–}}</ref>

Before granting independence to Mauritius, the United Kingdom paid {{GBP|3{{nbsp}}million}}{{when? |date=May 2025}} in compensation to the Mauritius Government and made several undertakings regarding the future status of the Chagos Archipelago. These included a commitment that the archipelago would be returned to Mauritius if it was no longer needed for defence purposes, assurances that Mauritius would retain access to navigational and meteorological facilities as well as fishing rights, and an agreement that any benefits from minerals or oil discovered in or near the Chagos Archipelago would revert to Mauritius. The compensation was intended to support development projects and address the resettlement of the displaced Chagossian community, though its adequacy and distribution have remained subjects of controversy.<ref name="Annex 65ICJ">{{Cite web|title=Annex 65 - U.K. Colonial Office, Despatch No. 423 to the Governor of Mauritius, PAC 93/892/01, FO 371/184529|url=https://www.icj-cij.org/sites/default/files/case-related/169/169-20180301-WRI-05-02-EN.pdf|publisher=[[International Court of Justice]]|date=6 October 1965|access-date=26 February 2025}}</ref> Various press articles have wrongly suggested that the £3{{nbsp}}million payment was for the purchase of the islands from Mauritius, when in fact it was compensation tied to the detachment of the archipelago and broader commitments made by the British government.<ref name="1965sale">{{cite book|title=Colonialism: An International Social, Cultural, and Political Encyclopedia|url=https://books.google.com/books?id=qFTHBoRvQbsC&pg=PA375|publisher=ABC-CLIO|isbn=978-1-57607-335-3|pages=375–|year = 2003}}</ref>

On 25 May 1967, less than two years after the agreement with Premier Seewoosagur Ramgoolam, Prime Minister Harold Wilson attended a Cabinet Committee meeting alongside the Chancellor of the Exchequer and the Secretaries of State for Commonwealth Affairs, Economic Affairs, Defence, and the Home Department. During this meeting, the Commonwealth Secretary noted that at the time of the 1965 agreement, Mauritian ministers were unaware of Britain's negotiations with the United States for a financial contribution toward the compensation. Mauritian officials were also informed that there would be no additional contribution from the United States, as this was a matter solely between the UK and Mauritius. The British government made it clear that the £3 million was the maximum it could afford and that if Mauritius did not accept the proposal, the UK would not proceed with arrangements for granting independence.<ref name="Annex 90ICJ">{{Cite web|title=Annex 90 - U.K. Defence and Oversea Policy Committee, Minutes of a Meeting held at 10 Downing Street, S.W.1., on Thursday, 25th May 1967 at 9:45 a.m., OPD(67)|url=https://www.icj-cij.org/sites/default/files/case-related/169/169-20180301-WRI-05-02-EN.pdf|publisher=[[International Court of Justice]]|date=25 May 1967|access-date=26 February 2025}}</ref>

During the same meeting, the Secretary of State for Defence stated that when the British Indian Ocean Territory was established, the UK had arranged compensation for both Mauritius and the Seychelles for the detachment of islands, with a total budget of approximately £10 million. The United States had agreed to contribute up to half of this amount, with a maximum of £5 million. To avoid potential embarrassment in the US Congress, the US government requested that its financial contribution remain secret. As a result, it was arranged that the US contribution would be concealed by waiving certain payments owed by the UK to the US in connection with the development of the Polaris missile program.<ref name="Annex 65ICJ"/><ref name="Annex 48PCA">{{Cite web|title=ANNEX 48 - Minute dated 12 May 1967 from the Secretary of State for Defence to the Foreign Secretary, FO 16/226|url=https://files.pca-cpa.org//pcadocs/mu-uk/Annexes%20to%20Memorial/MM%20Annexes%201-80.pdf|publisher=[[Permanent Court of Arbitration]]|date=12 May 1967|access-date=26 February 2025}}</ref>

On 30 December 1966, the United States and the United Kingdom executed an agreement through an Exchange of Notes which permit the [[United States Armed Forces]] to use any island of the BIOT for defence purposes for 50 years, until December 2016,<ref name="1965sale"/> followed by a 20-year optional extension (to 2036) to which both parties must agree by December 2014. {{As of|2010}}, only the atoll of Diego Garcia has been transformed into a military facility.

In 1967 the British Government bought the entire assets and real property of the [[Seychellois]] Chagos Agalega Company,<ref name="EversKooy2011">{{cite book|author1=Sandra Evers|author2=Marry Kooy|title=Eviction from the Chagos Islands: Displacement and Struggle for Identity Against Two World Powers|url=https://books.google.com/books?id=Q-sQISQZKhoC&pg=PA177|date=2011|publisher=Brill|isbn=978-90-04-20260-3|pages=177–}}</ref> which owned all the islands of the BIOT,<ref name="Allen2014">{{cite book|author=Stephen Allen|title=The Chagos Islanders and International Law|url=https://books.google.com/books?id=VOrsBQAAQBAJ&pg=PA277|date=2014|publisher=Bloomsbury Publishing|isbn=978-1-78225-474-4|pages=277–}}</ref> for £660,000,<ref name="Vine2011">{{cite book|author=David Vine|title=Island of Shame: The Secret History of the U.S. Military Base on Diego Garcia|url=https://books.google.com/books?id=3ankJb0skpwC&pg=PA92|date= 2011|publisher=Princeton University Press|isbn=978-1-4008-3850-9|pages=92–}}</ref> equivalent to {{GBP|{{Inflation|UK-GDP|{{#expr:660000/10^6}}|1967|r=1}}{{nbsp}}million|link=no}} in {{Inflation/year|UK-GDP}}, and administered them as a government enterprise while awaiting US funding of its proposed facilities, with an interim objective of paying for the administrative expenses of the new territory. The plantations, under their previous private ownership and under government administration, proved consistently unprofitable due to the introduction of new oils and lubricants in the international marketplace and the establishment of vast coconut plantations in the [[East Indies]] and the [[Philippines]].

Between 1967 and 1973, the population was forcibly removed from the islands and moved to Mauritius and the [[Seychelles]] to make way for a joint United States–United Kingdom military base on [[Diego Garcia]].<ref>{{cite news|url=http://news.bbc.co.uk/1/hi/england/7075361.stm|title=Exiles lose appeal over benefits|date=2 November 2007|work=[[BBC Online]]|access-date=5 November 2007|archive-date=11 January 2009|archive-url=https://web.archive.org/web/20090111111840/http://news.bbc.co.uk/1/hi/england/7075361.stm|url-status=live}}</ref> In March 1971, [[Seabee|United States naval construction battalions]] (Seabees), arrived on Diego Garcia to begin the construction of the Communications Station and an airfield. To satisfy the terms of an agreement between the United Kingdom and the United States for an uninhabited island, the plantation on Diego Garcia was closed in October of that year.<ref name="KaufmanMacpherson2005">{{cite book|author1=Will Kaufman|first2=Heidi Slettedahl |last2=Macpherson|title=Britain and the Americas: Culture, Politics, and History : a Multidisciplinary Encyclopedia|url=https://books.google.com/books?id=HbBbn3x7PZsC&pg=PA319|year=2005|publisher=ABC-CLIO|isbn=978-1-85109-431-8|pages=319–}}</ref>

The plantation workers and their families were initially deported to the plantations on [[Peros Banhos]] and [[Salomon Islands|Salomon atolls]] in the group; those who requested were transported to the Seychelles or Mauritius. In 1972, the UK closed the remaining plantations (all being now uneconomic) of the Chagos, and deported the Ilois who would have faced economic hardship to the Seychelles or Mauritius. The independent Mauritian government refused to accept these further displaced islanders without payment and in 1973, the United Kingdom agreed and gave them an additional £650,000, equivalent to {{GBP|{{Inflation|UK-GDP|{{#expr:650000/10^6}}|1973|r=1}}{{nbsp}}million|link=no}} in {{Inflation/year|UK-GDP}}, as reparation payments to resettle the people.<ref name="Jeffery2013">{{cite book|author=Laura Jeffery|title=Chagos Islanders in Mauritius and the UK: Forced displacement and onward migration|url=https://books.google.com/books?id=EdSuCQAAQBAJ&pg=PT50|date= 2013|publisher=[[Manchester University Press]]|isbn=978-1-84779-789-6|pages=50}}</ref> Some people were of the view that they were rehoused and employed under worse conditions than other Mauritians. The islands were becoming costly to live in due to industrial moves away from coconut oils and copra fibre markets and the success of larger plantations in the far east.

===2000–present===
{{see also|Depopulation of Chagossians from the Chagos Archipelago|UNROW Human Rights Impact Litigation Clinic#International Human Rights: The Chagos Islanders}}
[[File:US Air Force 030320-F-4338B-042 Busy bombers.jpg|thumb|[[B-2 bomber]] takeoff, [[B-52 bomber]]s on tarmac on Diego Garcia in 2003]]
In 2002, [[Diego Garcia]] was used twice for US [[Extraordinary rendition|rendition]] flights.<ref>{{cite news |title=In full: Miliband rendition statement |url=http://news.bbc.co.uk/2/hi/uk_news/politics/7257500.stm |access-date=31 May 2019 |publisher=BBC |date=21 February 2008 |archive-date=31 May 2019 |archive-url=https://web.archive.org/web/20190531044918/http://news.bbc.co.uk/2/hi/uk_news/politics/7257500.stm |url-status=live }}</ref>

On 13 October 2009, the Cabinet of the Maldives Government decided to see if the Maldives can claim for an extended continental shelf.<ref>{{cite press release |url=https://www.presidencymaldives.gov.mv/Press/Article/615 |website=presidencymaldives.gov.mv |date=13 October 2009 |access-date=29 October 2024 |title=Government to make a claim for extended continental shelf}}</ref>

On 26 July 2010, the Republic of Maldives submitted to the Commission on the Limits of the Continental Shelf, in accordance with Article 76, paragraph 8, of the [[United Nations Convention on the Law of the Sea]], information on the limits of the [[continental shelf]] beyond {{convert|200|nmi|link=in}} from the baselines from which the breadth of the territorial sea is measured.<ref>{{cite web |url=https://www.un.org/depts/los/clcs_new/submissions_files/submission_mdv_53_2010.htm |access-date=29 October 2024 |archive-date=15 November 2024 |archive-url=https://web.archive.org/web/20241115041633/https://www.un.org/depts/los/clcs_new/submissions_files/submission_mdv_53_2010.htm |work=Division for Ocean Affairs and the Law of the Sea, [[United Nations Office of Legal Affairs|Office of Legal Affairs]], United Nations |title=Commission on the Limits of the Continental Shelf (CLCS) Outer limits of the continental shelf beyond 200 nautical miles from the baselines: Submissions to the Commission: Submission by the Republic of Maldives |date=29 July 2024 |orig-date=28 July 2010 |url-status=live}}</ref>

On 1 April 2010, the British government announced the establishment of the [[Chagos Marine Protected Area]] as the world's largest [[marine reserve]]. At {{cvt|640,000|km2}}, it is larger than both France and the US state of [[California]]. It doubled the total area of environmental no-take zones worldwide.<ref name="Managing Protected">{{cite web |title=Managing Marine Protected Areas a case study examining the Chagos Archipelago |first1=Peter |last1=Liss |first2=Rodney |last2=Anderson |url=http://nsmc.eu.com/Marine-Protected-Areas-Report-3.pdf |archive-url=https://web.archive.org/web/20130530213720/http://nsmc.eu.com/Marine-Protected-Areas-Report-3.pdf |url-status=usurped |archive-date=30 May 2013 |publisher=North Sea Marine Cluster |access-date=5 February 2013}}</ref> On 18 March 2015, the [[Permanent Court of Arbitration]] unanimously held that the [[Chagos Marine Protected Area|marine protected area]] (MPA) which the United Kingdom declared around the Chagos Archipelago in April 2010 violates international law. [[Anerood Jugnauth]], [[Prime Minister of Mauritius]], pointed out that it is the first time that the United Kingdom's conduct with regard to the Chagos Archipelago has been considered and condemned by any international court or tribunal.<ref name="alla" /><ref name="govmu.org" />

On 20 December 2010 Mauritius initiated proceedings against the United Kingdom under the [[United Nations Convention on the Law of the Sea]] (UNCLOS) to challenge the legality of the Chagos Archipelago MPA.<ref>{{cite web |archive-url=https://web.archive.org/web/20241115043859/https://pca-cpa.org/en/cases/11/ |url-status=live |archive-date=15 November 2024 |access-date=15 November 2024 |orig-date=20 December 2010 |date=18 March 2015 |location=Permanent Court of Arbitration [[Peace Palace]] Carnegieplein [[The Hague]] The Netherlands |publisher=Permanent Court of Arbitration |website=pca-cpa.org |url=https://pca-cpa.org/en/cases/11/ |title=Chagos Marine Protected Area Arbitration (Mauritius v. United Kingdom)}}</ref>

The issue of compensation and repatriation of the former inhabitants of several of the archipelago's atolls, exiled since 1973, continued in litigation, and in 2010 it was submitted to the [[European Court of Human Rights]] by a group of former residents.<ref>{{cite news|url=http://www.timesonline.co.uk/tol/news/environment/article7052088.ece|url-status=dead|archive-url=https://web.archive.org/web/20110924105418/http://www.timesonline.co.uk/tol/news/environment/article7052088.ece|archive-date=2011-09-24|title=Chagossians fight for a home in paradise|date=2010-03-06 |newspaper=[[The Sunday Times]]|first=Catherine|last=Philp|access-date=2012-06-21}}</ref>

Litigation continued in 2012 regarding the right of return for the displaced islanders and Mauritian sovereignty claims. In addition, advocacy on the Chagossians' behalf continues both in the United States and in Europe. In 2018, Mauritius took the matter to the [[International Court of Justice]] for an advisory opinion, against British objections.<ref name="bully">{{Cite web |url=https://www.bbc.co.uk/news/world-africa-45300739 |title=Chagos Islands dispute: UK 'threatened' Mauritius |last=Harding |first=Andrew |date=27 August 2018 |publisher=[[BBC]] |access-date=27 August 2018 |archive-date=27 August 2018 |archive-url=https://web.archive.org/web/20180827204839/https://www.bbc.co.uk/news/world-africa-45300739 |url-status=live }}</ref>

In 2014, a Feasibility Study for the Resettlement of the British Indian Ocean Territory was undertaken by the UK Government by consultants from [[KPMG]].

The objectives of the study were to assess costs and sustainability of resettlement over five, ten, and twenty years, evaluate economic self-sufficiency, risks, and environmental implications, explore potential resettlement options ranging from small-scale pilot projects to larger-scale resettlements.

A neutral analysis was undertaken, including consultations with the Chagossian community and environmental assessments.
Options considered included modern lifestyles, subsistence living, eco-villages, and research stations.
Legal, environmental, infrastructure, and economic aspects were analysed.

Large-scale resettlement (1,500 people), medium-scale (500 people), and a pilot scheme (150 people) were proposed. Diego Garcia was a preferred location due to existing infrastructure, with {{lang |fr |Ile du Coin}} and Boddam also being provisional initial candidate sites.

Chagossians expressed a strong preference for permanent resettlement, not temporary visits.
They emphasized the need for modern living standards, environmental conservation, and access to UK-level education and healthcare.

Most islands are low-lying and vulnerable to climate change, with varying suitability for habitation.
Environmental protections and monitoring would be critical.

Employment opportunities could include tourism, fishing, and environmental monitoring.
High-end and eco-tourism were seen as potential revenue generators.

Amendments to BIOT's legal framework would be required to facilitate resettlement. Governance models could draw from other small British Overseas Territories like [[Pitcairn Islands|Pitcairn]] and [[Ascension Island]].<ref>{{cite web |url=https://www.gov.uk/government/speeches/policy-review-of-resettlement-of-the-british-indian-ocean-territory |archive-date=30 December 2024 |url-status=live |archive-url=https://web.archive.org/web/20241230001800/https://www.gov.uk/government/speeches/policy-review-of-resettlement-of-the-british-indian-ocean-territory |title=Policy Review of Resettlement of the British Indian Ocean Territory |location=[[Parliament of the United Kingdom|Parliament]] |work=Written statement to Parliament |access-date=19 December 2024 |date=10 February 2015 |author1=Foreign & Commonwealth Office |author2=The Rt Hon Hugo Swire |author-link2=Hugo Swire |author-link1=Foreign, Commonwealth and Development Office }}</ref><ref>{{cite web |url=https://data.parliament.uk/DepositedPapers/Files/DEP2014-1543/Feasibility_Study_for_the_Resettlement_of_the_BIOT_Draft_Report.pdf |title=Feasibility Study for the Resettlement of the British Indian Ocean Territory |date=13 November 2014 |at=Draft Report |work=[[KPMG]] |archive-date=30 December 2024 |url-status=live |archive-url=https://web.archive.org/web/20241230003306/https://data.parliament.uk/DepositedPapers/Files/DEP2014-1543/Feasibility_Study_for_the_Resettlement_of_the_BIOT_Draft_Report.pdf}}</ref>{{Page needed|date=December 2024}}

In November 2016, the United Kingdom restated it would not permit Chagossians to return to the islands.<ref name="Guardian: Chagos islanders cannot return home">{{cite news|url=https://www.theguardian.com/world/2016/nov/16/chagos-islanders-cannot-return-home-uk-foreign-office-confirms|title=Chagos islanders cannot return home, UK Foreign Office confirms|first=Owen|last=Bowcott|date=16 November 2016|access-date=26 August 2017|newspaper=The Guardian|archive-date=23 September 2021|archive-url=https://web.archive.org/web/20210923061810/https://www.theguardian.com/world/2016/nov/16/chagos-islanders-cannot-return-home-uk-foreign-office-confirms|url-status=live}}</ref>

In July 2021, the [[Chagos Refugee Group|Chagos Refugees Group UK]] submitted a complaint to the Irish government against domain-name speculators [[Paul Kane (entrepreneur)|Paul Kane]] and [[Ethos Capital]] subsidiary [[Afilias]], seeking repatriation of the [[.io]] (that is, [[Indian Ocean]]) country-code top-level domain and payment of back royalties from the {{USD|7{{nbsp}}million}} per year in revenue generated by the domain.<ref>{{cite web |last1=Levy |first1=Jonathan |title=Complaint Filed Against Afilias Ltd. (Ireland) including its subsidiaries 101domain GRS Limited (Ireland), Internet Computer Bureau Limited (England & British Indian Ocean Territory) In Respect of OECD Guidelines Violations in Operation of ccTLD .io Before the Ireland OECD National Contact Point |url=http://www.jlevy.co/wp-content/uploads/2021/07/OECD-July-28-2021-Afilias-Ltd.pdf |archive-date=15 November 2024 |archive-url=https://web.archive.org/web/20241115045938/http://www.jlevy.co/wp-content/uploads/2021/07/OECD-July-28-2021-Afilias-Ltd.pdf |url-status=live |publisher=Chagos Refugees Group UK |access-date=2 August 2021}}</ref> While attempts to repatriate top-level domains are not uncommon, this one is notable in that it cites consumer and human rights violations of the [[OECD]]'s 2011 [[OECD Guidelines for Multinational Enterprises|Guidelines for Multinational Enterprises]] rather than [[Multistakeholder governance|multistakeholder representation]] under [[ICANN]] policy, and because the .io domain has enjoyed commercial success, particularly among [[cryptocurrency]] companies, with more than 270,000 domains registered.<ref>{{cite web |last1=Murphy |first1=Kevin |title=Afilias bought .io for $70 million |date=9 November 2018 |url=http://domainincite.com/23650-afilias-bought-io-for-70-million |publisher=Domain Incite |access-date=2 August 2021 |archive-date=2 August 2021 |archive-url=https://web.archive.org/web/20210802044813/http://domainincite.com/23650-afilias-bought-io-for-70-million |url-status=live }}</ref><ref>{{cite web |last1=Goldstein |first1=David |title=Chagos Islanders Lodge Complaint With OECD to Get Their .IO Back |date=30 July 2021 |url=https://goldsteinreport.com/chagos-islanders-lodge-complaint-with-oecd-to-get-their-io-back/ |publisher=Goldstein Report |access-date=2 August 2021 |archive-date=2 August 2021 |archive-url=https://web.archive.org/web/20210802044809/https://goldsteinreport.com/chagos-islanders-lodge-complaint-with-oecd-to-get-their-io-back/ |url-status=live }}</ref>

==Sovereignty dispute==
{{Main|Chagos Archipelago sovereignty dispute}}
The Chagos had been administered from imperial offices in Mauritius since the 18th century when the French first named the islands. All of the islands forming part of the French colonial territory of {{lang |fr |[[Isle de France (Mauritius)|Isle de France]]}} (as Mauritius was often then known) were ceded to the British in 1810 under the [[History of Mauritius#French rule (1715–1810)|Act of Capitulation]]. In 1965, in planning before Mauritian independence, the UK split the archipelago from the territory of Mauritius to form the British Indian Ocean Territory, looking to provide the United States, which was the country's main creditor following the turmoil of the Second World War, with an uninhabited island base,.<ref name="real">{{cite web|url=http://www.realclearworld.com/articles/2012/04/06/mauritius_chagos_archipelago_diego_garcia_99999.html|title=Time for UK to Leave Chagos Archipelago|date=6 April 2012|publisher=Real clear world|access-date=12 July 2012|archive-date=11 May 2012|archive-url=https://web.archive.org/web/20120511010759/http://www.realclearworld.com/articles/2012/04/06/mauritius_chagos_archipelago_diego_garcia_99999.html|url-status=live}}</ref>

The United Nations' resolutions on self-determination deprecated the parcelling up of imperial territories before independence, without its endorsement and local support, mindful of the [[Partition of India]] which provided the strong governments sought by the separate factions but failed to ensure a relatively peaceful transfer of power in many places. Mauritius has repeatedly stated that the British claim that the Chagos Archipelago is one of its territories thwarted its claim to what would be widely considered part of the Mauritian colony and also breached UN resolutions. The UK has stated that the Chagos will be assigned to Mauritius once the islands are no longer required for defence purposes.<ref name="real" />

The island nation of Mauritius claims the Chagos Archipelago (which is coterminous with the BIOT), including Diego Garcia. Maldives states that the UK's claim to a {{convert|200|nmi|adj=on}} [[Exclusive Economic Zone]] around the Chagos Archipelago is invalid as the islands are considered uninhabited.{{clarify|date=November 2021}}<!--terra nullius?--><ref name="maldivesindependent.com">{{Cite web|url=https://maldivesindependent.com/politics/maldives-defends-un-vote-on-chagos-islands-dispute-145501|title=Maldives defends UN vote on Chagos Islands dispute|website=Maldives Independent|date=May 23, 2019|access-date=28 December 2019|archive-date=7 June 2019|archive-url=https://web.archive.org/web/20190607183708/https://maldivesindependent.com/politics/maldives-defends-un-vote-on-chagos-islands-dispute-145501|url-status=live}}</ref> A subsidiary issue is the Mauritian opposition to the 1 April 2010 UK Government's declaration that the BIOT is a [[Marine Protected Area]] with fishing and extractive industry (including oil and gas exploration) prohibited.<ref>{{cite web|url=http://www.afriqueavenir.org/en/2010/05/14/mauritius-to-reiterate-its-conditions-for-renewed-talks-with-uk-on-chagos/ |title=Mauritius to reiterate its conditions for renewed talks with UK on Chagos |website=Afrique Avenir|date=14 May 2010|access-date=2011-12-23 |url-status=dead |archive-url=https://web.archive.org/web/20111223113708/http://www.afriqueavenir.org/en/2010/05/14/mauritius-to-reiterate-its-conditions-for-renewed-talks-with-uk-on-chagos/ |archive-date=2011-12-23}}</ref>

On 16 November 2016, the UK Foreign Office maintained their ban on [[repatriation]] of the islands.<ref name="Guardian: Chagos islanders cannot return home" /> In response to this decision, the Prime Minister of Mauritius expressed his country's plan to advance the sovereignty dispute to the [[International Court of Justice]].<ref>{{Cite news|url=http://www.theguardian.com/world/2016/nov/17/mauritius-threatens-to-take-chagos-islands-row-to-un-court|title=Mauritius threatens to take Chagos Islands row to UN court|first=Owen|last=Bowcott|date=17 November 2016|newspaper=The Guardian}}</ref> British Foreign Secretary [[Boris Johnson]] sought Indian assistance for resolving the dispute involving the UK, the US, and Mauritius. India has maintained considerable influence in Mauritius through deep cultural and economic ties. India has maintained that the matter of whether or not to proceed with the UN General Assembly move is a decision for the Mauritian government to make.<ref>{{cite news|url=http://www.thehindu.com/news/international/U.K.-seeks-Indian-help-in-resolving-Chagos-Archipelago-dispute/article17063926.ece|title=U.K. seeks Indian help in resolving Chagos Archipelago dispute|last=Ram|first=Vidya|newspaper=The Hindu|date=19 January 2017|access-date=26 August 2017|archive-date=11 November 2020|archive-url=https://web.archive.org/web/20201111224337/https://www.thehindu.com/news/international/U.K.-seeks-Indian-help-in-resolving-Chagos-Archipelago-dispute/article17063926.ece|url-status=live}}</ref>

On 22 June 2017, the [[United Nations General Assembly]] (UNGA) requested the [[International Court of Justice]] (ICJ) to give an advisory opinion on the separation of the Chagos Archipelago from Mauritius. On 25 February 2019, the International Court of Justice advised that in its opinion:
* "at the time of its detachment from Mauritius" the "Chagos Archipelago was clearly an integral part of that non-self-governing territory";<ref name="Chagos Archipelago">{{Cite web|last=International Court of Justice|date=25 February 2019|title=Advisory Opinion on the Legal Consequences of the Separate of the Chagos Archipelago from Mauritius in 1965|url=https://www.icj-cij.org/public/files/case-related/169/169-20190225-ADV-01-00-EN.pdf|url-status=live|website=International Court of Justice|archive-url=https://web.archive.org/web/20201101111656/https://www.icj-cij.org/public/files/case-related/169/169-20190225-ADV-01-00-EN.pdf |archive-date=1 November 2020}}</ref>
* the United Kingdom's purported detachment of the Chagos Archipelago "was not based on the free and genuine expression of the will of the people concerned";<ref name="Chagos Archipelago" />
* at the time of the purported detachment, "obligations arising under international law and reflected in the resolutions adopted by the General Assembly during the process of decolonization of Mauritius require[d] the United Kingdom, as the administering Power, to respect the territorial integrity of that country, including the Chagos Archipelago";<ref name="Chagos Archipelago" />
* the "detachment" was therefore "unlawful" such that "the process of decolonization of Mauritius was not lawfully completed when Mauritius acceded to independence in 1968"<ref name="Chagos Archipelago" />
* "the United Kingdom's continued administration of the Chagos Archipelago constitutes a wrongful act entailing the international responsibility of that State";<ref name="Chagos Archipelago" />
* this "unlawful act" is "of a continuing character" and "the United Kingdom is under an obligation to bring to an end its administration of the Chagos Archipelago as rapidly as possible";<ref name="Chagos Archipelago" /> and 
* "all Member States [of the United Nations] are under an obligation to co-operate with the United Nations in order to complete the decolonization of Mauritius."<ref name="Chagos Archipelago" />

On 23 June 2017, the UNGA voted in favour of referring the territorial dispute between Mauritius and the United Kingdom to the ICJ in order to clarify the legal status of the Chagos Islands archipelago in the Indian Ocean. The motion was approved by a majority vote with 94 voting for and 15 against.<ref>{{cite news|last1=Sengupta|first1=Somini|date=22 June 2017|title=U.N. Asks International Court to Weigh In on Britain-Mauritius Dispute|newspaper=The New York Times|url=https://www.nytimes.com/2017/06/22/world/europe/uk-mauritius-chagos-islands.html|access-date=23 June 2017|archive-date=27 December 2019|archive-url=https://web.archive.org/web/20191227214438/https://www.nytimes.com/2017/06/22/world/europe/uk-mauritius-chagos-islands.html|url-status=live}}</ref><ref>{{cite news|date=22 June 2017|title=Chagos legal status sent to international court by UN|work=BBC News|url=https://www.bbc.com/news/uk-40376673|access-date=23 June 2017|archive-date=3 July 2021|archive-url=https://web.archive.org/web/20210703075109/https://www.bbc.com/news/uk-40376673|url-status=live}}</ref>

On 22 May 2019, the United Nations General Assembly debated and adopted a resolution that affirmed that the Chagos archipelago "forms an integral part of the territory of Mauritius." The resolution demanded that the UK "withdraw its colonial administration ... unconditionally within a period of no more than six months." 116 states voted in favour of the resolution, 55 abstained and only 5 countries supported the [[United Kingdom]]. During the debate, the Mauritian Prime Minister, [[Anerood Jugnauth|Sir Anerood Jugnauth]], described the expulsion of Chagossians as "akin to a [[Crimes against humanity|crime against humanity]]", while the United Kingdom continued to assert that it had no doubt about its sovereignty over the archipelago.<ref name="Resolution">{{Cite news |last=Sands |first=Philippe |author-link=Philippe Sands |date=2019-05-24 |quote=Britain’s behaviour towards its former colony has been shameful. The UN resolution changes everything |title=At last, the Chagossians have a real chance of going back home |url=https://www.theguardian.com/commentisfree/2019/may/24/chagossians-britain-colony-shameful-un-resolution? |newspaper=The Guardian |access-date=5 June 2019 |archive-date=5 February 2021 |archive-url=https://web.archive.org/web/20210205232500/https://www.theguardian.com/commentisfree/2019/may/24/chagossians-britain-colony-shameful-un-resolution |url-status=live }}</ref> The Maldives were one of the countries which supported the UK in the General Assembly vote. It stated that, if the Chagos Archipelago became inhabited, the Maldives claim to an extension of its [[Exclusive Economic Zone]] would be affected. The resolution's immediate consequence was that the UN and other international organisations became bound by UN law to support the decolonisation of the Chagos Islands.

On 25 February 2019, the ICJ delivered an advisory opinion that placing the Archipelago under British administration in 1965 was not based upon the free expression of the inhabitants and that it thus advised that the United Kingdom should relinquish the archipelago, including the strategic United States military base, for the establishment of which approximately 1,500 inhabitants had been deported. The [[Government of the United Kingdom|British government]] rejected any jurisdiction of the court to deliberate these matters.<ref>{{cite news|title=UN court rejects UK's claim of sovereignty over Chagos Islands|url=https://www.theguardian.com/world/2019/feb/25/un-court-rejects-uk-claim-to-sovereignty-over-chagos-islands|date=25 February 2019|newspaper=The Guardian|first=Owen|last=Bowcott|access-date=25 February 2019|archive-date=14 June 2021|archive-url=https://web.archive.org/web/20210614153348/https://www.theguardian.com/world/2019/feb/25/un-court-rejects-uk-claim-to-sovereignty-over-chagos-islands|url-status=live}}</ref>

The UNGA voted in favour of setting a six-month deadline for the United Kingdom to withdraw from the Chagos Archipelago, which would then be reunified with Mauritius. The motion was approved by a majority vote with 116 voting for and 6 against. Fifty-six states, including France and Germany, abstained.<ref>{{Cite news|url=https://www.bbc.com/news/uk-48371388|title=Chagos Islands dispute: UN backs end to UK control|work=BBC News|date=22 May 2019|access-date=3 February 2021|archive-date=13 March 2023|archive-url=https://web.archive.org/web/20230313173529/https://www.bbc.com/news/uk-48371388|url-status=live}}</ref><ref>{{cite news|title=UK suffers crushing defeat in UN vote on Chagos Islands|url=https://www.theguardian.com/world/2019/may/22/uk-suffers-crushing-defeat-un-vote-chagos-islands|date=22 May 2019|newspaper=The Guardian|first=Owen|last=Bowcott|author2=Julian Borger|access-date=22 May 2019|archive-date=23 May 2019|archive-url=https://web.archive.org/web/20190523022954/https://www.theguardian.com/world/2019/may/22/uk-suffers-crushing-defeat-un-vote-chagos-islands|url-status=live}}</ref>

On 28 January 2021, the United Nation's [[International Tribunal for the Law of the Sea]] (ITLOS) confirmed the International Court of Justice ruling and ordered Britain to hand over the Chagos Archipelago to Mauritius.<ref>{{Cite news|date=2021-01-28|title=UN court rules UK has no sovereignty over Chagos islands|language=en-GB|work=BBC News|url=https://www.bbc.com/news/world-africa-55848126|access-date=2021-01-28}}</ref> The ITLOS Special Chamber affirmed that: "it is inconceivable that the United Kingdom, whose administration over the Chagos Archipelago constitutes a wrongful act of a continuing character and thus must be brought to an end as rapidly as possible, and yet who has failed to do so, can have any legal interests in permanently disposing of maritime zones around the Chagos Archipelago by delimitation".<ref>{{Cite web|work=International Tribunal for the Law of the Sea|date=28 January 2021|title=Dispute Concerning Delimitation of the Maritime Boundary Between Mauritius and Maldives in the Indian Ocean (Mauritius/Maldives)|url=https://www.itlos.org/securedl/sdl-eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpYXQiOjE2MjAwNDEzODIsImV4cCI6MTYyMDEzMTM4MiwidXNlciI6MCwiZ3JvdXBzIjpbMCwtMV0sImZpbGUiOiJmaWxlYWRtaW5cL2l0bG9zXC9kb2N1bWVudHNcL2Nhc2VzXC8yOFwvcHJlbGltaW5hcnlfb2JqZWN0aW9uc1wvQzI4X0p1ZGdtZW50X3ByZWxpbW9ial8yOC4wMS4yMDIxX29yaWcucGRmIiwicGFnZSI6MTA2Nn0.mnVoeQuH0fmpTQ3KBcziu0nWFy50rkPYUb2Kw5TUNwM/C28_Judgment_prelimobj_28.01.2021_orig.pdf|url-status=live|archive-url=https://web.archive.org/web/20210503113026/https://www.itlos.org/securedl/sdl-eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpYXQiOjE2MjAwNDEzODIsImV4cCI6MTYyMDEzMTM4MiwidXNlciI6MCwiZ3JvdXBzIjpbMCwtMV0sImZpbGUiOiJmaWxlYWRtaW5cL2l0bG9zXC9kb2N1bWVudHNcL2Nhc2VzXC8yOFwvcHJlbGltaW5hcnlfb2JqZWN0aW9uc1wvQzI4X0p1ZGdtZW50X3ByZWxpbW9ial8yOC4wMS4yMDIxX29yaWcucGRmIiwicGFnZSI6MTA2Nn0.mnVoeQuH0fmpTQ3KBcziu0nWFy50rkPYUb2Kw5TUNwM/C28_Judgment_prelimobj_28.01.2021_orig.pdf |archive-date=3 May 2021}}</ref>

In August 2021, the [[Universal Postal Union]] banned BIOT stamps from being used in the BIOT, a move Mauritian Prime Minister [[Pravind Jugnauth]] called a "big step in favour of the recognition of the sovereignty of Mauritius over the Chagos".<ref>{{Cite news |date=26 August 2021 |title=UN bans British stamps in Chagos island |url=https://www.thehindu.com/news/international/un-bans-british-stamps-in-chagos-island/article36127741.ece |url-status=live |archive-url=https://web.archive.org/web/20220609191117/https://www.thehindu.com/news/international/un-bans-british-stamps-in-chagos-island/article36127741.ece |archive-date=9 June 2022 |access-date=27 August 2021 |newspaper=The Hindu}}</ref>{{Failed verification|date=November 2024}}

On November 26, 2021, Mauritius amended its Criminal Code through the Criminal Code (Amendment) Act 2021 to introduce Section 76B, which criminalizes actions that misrepresent Mauritius' sovereignty over any part of its territory. The law applies to individuals acting under the authority, instructions, or financial support (direct or indirect) of a foreign state and imposes penalties of a fine or imprisonment of up to 10 years. Offenses include producing, distributing, or marketing coins, stamps, maps, or official documents that misrepresent Mauritius' sovereignty, as well as instructing others to do so. A "foreign state" under this provision refers to any country that an international court or tribunal has determined to have no valid claim over any part of Mauritius' territory.<ref>{{cite act|title=THE CRIMINAL CODE (AMENDMENT) ACT 2021 |date=19 November 2021|url=https://mauritiusassembly.govmu.org/mauritiusassembly/wp-content/uploads/2023/03/act1721.pdf |access-date=6 October 2024}}</ref>

On 14 February 2022, a delegation from Mauritius, including the Mauritian ambassador to the UN, raised the Mauritian flag on the Chagossian atoll of [[Peros Banhos]]. The move was done in the context of a scientific survey of Blenheim Reef but was regarded as a formal challenge to British sovereignty over Chagos.<ref>{{Cite web|date=2022-02-14|title=Mauritius formally challenges Britain's ownership of Chagos Islands|url=https://www.theguardian.com/world/2022/feb/14/mauritius-formally-challenges-britains-ownership-of-chagos-islands|author1=Owen Bowcott |author2= Bruno Rinvolucri |access-date=2022-02-14|newspaper=The Guardian|language=en}}</ref>

On 3 November 2022, the British Foreign Secretary [[James Cleverly]] announced that the UK and Mauritius had decided to begin negotiations on sovereignty over the British Indian Ocean Territory, taking into account the recent international legal proceedings. Both states had agreed to ensure the continued operation of the joint UK/US military base on Diego Garcia.<ref name=guardian-20221103>{{cite news |url=https://www.theguardian.com/world/2022/nov/03/uk-agrees-to-negotiate-with-mauritius-over-handover-of-chagos-islands |title=UK agrees to negotiate with Mauritius over handover of Chagos Islands |last=Wintour |first=Patrick |newspaper=The Guardian |date=3 November 2022 |access-date=3 November 2022 |archive-date=3 November 2022 |archive-url=https://web.archive.org/web/20221103141218/https://www.theguardian.com/world/2022/nov/03/uk-agrees-to-negotiate-with-mauritius-over-handover-of-chagos-islands |url-status=live }}</ref><ref name=hansard-20221103>{{cite Hansard |url=https://hansard.parliament.uk/commons/2022-11-03/debates/22110340000007/ChagosArchipelago |volume=721 |position=The Secretary of State for Foreign, Commonwealth and Development Affairs |title=Chagos Archipelago |speaker=James Cleverly |jurisdiction=Parliament of the United Kingdom |id=HCWS354 |date=3 November 2022 |access-date=3 November 2022 |archive-date=4 November 2022 |archive-url=https://web.archive.org/web/20221104013303/https://hansard.parliament.uk/commons/2022-11-03/debates/22110340000007/ChagosArchipelago |url-status=live }}</ref> 

Whereas these talks included the resettlement of expelled Chagossians, Cleverly's successor as British foreign secretary, [[David Cameron]], later ruled out a return of the islanders.<ref>{{Cite news |last=Townsend |first=Mark |date=2024-01-26 |title=Chagos islanders stunned as David Cameron rules out return |url=https://www.theguardian.com/global-development/2024/jan/26/chagos-islanders-stunned-as-david-cameron-rules-out-return |access-date=2024-01-27 |work=The Guardian |language=en-GB |issn=0261-3077}}</ref>

On 3 October 2024, the UK Government made a joint statement with the Mauritian government that they had negotiated for the sovereignty of the Chagos Islands following two years of negotiation whilst still enabling the running of the American military base on Diego Garcia, thereby ruling out the right of return of the Chagossians to that specific island.<ref>{{cite press release |title=UK and Mauritius joint statement, 3 October 2024 |author1=Foreign, Commonwealth & Development Office |author2=Prime Minister's Office, 10 Downing Street |author3=The Rt Hon Sir Keir Starmer KCB KC MP |author-link3=Keir Starmer |url=https://www.gov.uk/government/news/joint-statement-between-uk-and-mauritius-3-october-2024 |website=GOV.UK |language=en |access-date=3 October 2024 |archive-date=3 October 2024 |archive-url=https://web.archive.org/web/20241003100358/https://www.gov.uk/government/news/joint-statement-between-uk-and-mauritius-3-october-2024 |url-status=live }}</ref> The Chagossian people living in the UK have criticised the deal for not having included the Chagossian community in the decision-making process.<ref>{{Cite web |last1=Davies |first1=Maia |last2=Hagan |first2=Rachel |date=3 October 2024 |title=Chagossians criticise lack of say in UK deal to hand over islands |url=https://www.bbc.co.uk/news/articles/cy78ejg71exo |access-date=6 October 2024 |website=BBC News |publisher=BBC}}</ref> and expressed concerns that their interests may not be fully safeguarded under Mauritian administration. However, many Chagossians, including those in Mauritius, support Mauritian sovereignty. The Chagos Refugees Group, the largest Chagossian advocacy organization, has been a leading voice for this position. Its leader, Olivier Bancoult, described the UK's decision to return the Chagos Archipelago to Mauritius and allow Chagossians to resettle on the outer islands as a significant step and an acknowledgment of past injustices.<ref name="govmu5">{{Cite web |date=3 October 2024 |title=PM meets Mr Bancoult following historic political agreement between Mauritius and UK on the exercise of sovereignty over Chagos Archipelago |url=https://govmu.org/EN/newsgov/SitePages/PM-meets-Mr-Bancoult-following-historic-political-agreement-between-Mauritius-and-UK-on-the-exercise-of-sovere.aspx |access-date=26 February 2025 |publisher=[[Government of Mauritius]]}}</ref><ref name="chagosref">{{Cite web |date=2019 |title=Olivier Bancoult: "It's a great victory for the Chagossian community" |url=https://thechagosrefugeesgroup.com/chagos-in-news/olivier-bancoult-its-a-great-victory-for-the-chagossian-community/ |access-date=26 February 2025 |publisher=Chagos Refugees Group}}</ref> On the same day, former Maldivian President [[Mohamed Nasheed]] stated that the decision to hand over the Chagos Islands to Mauritius, despite the Maldives' claims, was unacceptable.<ref name="ceding Chagos">{{Cite web |title=Nasheed says UK ceding Chagos to Mauritius unacceptable {{!}} Atoll Times |url=https://atolltimes.mv/post/news/10035 |access-date=2024-10-12 |website=atolltimes.mv |language=en |archive-date=4 October 2024 |archive-url=https://web.archive.org/web/20241004060919/https://atolltimes.mv/post/news/10035 |url-status=live }}</ref> On 6 October 2024, the [[The Democrats (Maldives)|Democrats Party]] of the Maldives expressed concern that Maldives President [[Mohamed Muizzu]]’s administration had not been making efforts to assert the Maldives' claim over the Chagos Archipelago, as promised in the presidential pledge.<ref>{{Cite web |title=The Democrats raise concern for inactive Chagos reclamation works |url=https://en.sun.mv/92389 |access-date=2024-10-12 |website=SunOnline International |language=en}}</ref> In December 2024, Muizzu sent an official letter to the United Kingdom, which he said asserted the Maldives' strong historical claim to the archipelago, although the specific text of the letter was not released.<ref name=SunMV-Letter>{{cite news|url=https://en.sun.mv/93729|title=Govt refuses to disclose letter sent to UK over Chagos dispute|website=SunOnline|quote=[Maldivian President Muizzu] said that given the documental evidence of the historical connections between Maldives and Chagos, Maldives has a greater claim over the territory than any other country.|access-date=18 April 2025|archive-date=11 February 2025|archive-url=https://web.archive.org/web/20250211081836/https://en.sun.mv/93729|url-status=live|date=8 December 2024}}</ref>

The deal was put on hold following the [[2024 United States presidential election]] to allow consideration from the [[Second cabinet of Donald Trump|new incoming US administration]].<ref>{{Cite news |last1=Crerar |first1=Pippa |last2=Walker |first2=Peter |date=2025-01-15 |title=UK stalls Chagos Islands deal until Trump administration can 'consider detail' |url=https://www.theguardian.com/world/2025/jan/15/uk-chagos-islands-handover-mauritius-donald-trump-diego-garcia |access-date=2025-01-17 |work=The Guardian |language=en-GB |issn=0261-3077}}</ref> On 27 February 2025, speaking in the [[Oval Office]] alongside UK Prime Minister [[Sir Keir Starmer]], US President [[Donald Trump]] stated that he was willing to support the agreement to transfer sovereignty of the Chagos Islands to Mauritius.<ref name="bbc27">{{cite web |date=27 February 2025 |title=Trump 'inclined' to back UK's Chagos Islands deal |url=https://www.bbc.com/news/articles/c5yxxjr8v2vo |access-date=28 February 2025 |publisher=[[BBC World]]}}</ref> In April, Trump signed off on the deal.<ref>{{Cite news |last=Fisher |first=Lucy |date=2025-04-01 |title=Donald Trump signs off Chagos Islands deal between UK and Mauritius |url=https://www.ft.com/content/e03ab89d-42fc-44ab-89fe-7ed086f0ab3a |access-date=2025-04-23 |work=Financial Times}}</ref>

There has been a consistent theme of negotiations and decisions about the Chagos Islands being made without directly involving or consulting the Chagossian community. This exclusion from the sovereignty negotiations between the UK and Mauritius has fuelled opposition among Chagossians, who feel their voices have been deliberately ignored in determining the future of their homeland. They demand full inclusion in any discussions or treaties regarding the Chagos Islands.<ref name="Controversy">{{cite news |url=https://www.bbc.co.uk/news/articles/crln9np2dz8o |access-date=22 December 2024 |archive-date=3 January 2025 |archive-url=https://web.archive.org/web/20250103012152/https://www.bbc.com/news/articles/crln9np2dz8o |url-status=live |work=BBC News |title=Hundreds protest against Chagos Islands deal |date=13 November 2024 |location=[[South East England|South East]] |first=Lucinda |last=Adam}}</ref>

The Chagossians have been engaged in numerous legal battles over their right to return and the sovereignty of the islands. Legal actions like those initiated by Bernadette Dugasse against the UK government for failing to include Chagossians in sovereignty talks further underscore their opposition to decisions made without their input. This reflects a broader struggle for recognition of their rights and sovereignty over their land.<ref name="Interests">{{cite news |url=https://inews.co.uk/news/chagos-island-fury-mauritius-uk-3309127?srsltid=AfmBOopGAXI-NtWr1gZmqDVFHnmMTbiRTXxKiHYPmuQxT1fNAK6GJUT9 |url-access=subscription |access-date=22 December 2024 |archive-date=3 January 2025 |url-status=live |archive-url=https://web.archive.org/web/20250103012843/https://inews.co.uk/news/chagos-island-fury-mauritius-uk-3309127?srsltid=AfmBOopGAXI-NtWr1gZmqDVFHnmMTbiRTXxKiHYPmuQxT1fNAK6GJUT9 |quote=Chagossians were not part of the negotiations over sovereignty, he said, despite the Foreign Office saying the interests of the community had been an important part of the talks. |first=Joe |last=Duggan |date=4 October 2024 |title='We've been betrayed': Chagos Islanders' fury as UK hands territory to Mauritius}}</ref>

On 22 May 2025 the Prime Minister of the United Kingdom Keir Starmer signed a formal agreement on the transfer of sovereignty of the Chagos Islands to Mauritius.<ref>{{Cite news |date=2025-05-23 |title=UK hands over Chagos Islands to Mauritius in landmark sovereignty deal |url=https://timesofindia.indiatimes.com/world/uk/uk-hands-over-chagos-islands-to-mauritius-in-landmark-sovereignty-deal/articleshow/121343441.cms |access-date=2025-05-23 |work=The Times of India |issn=0971-8257}}</ref>

Under the terms of the deal, the strategic atoll of Diego Garcia and its surrounding {{convert|24|mi|order=flip|adj=on}} buffer zone are immediately leased back to the UK. This arrangement permits the continued operation of the joint UK/US base on the island for the next 99 years, with an additional 40-year extension and a subsequent right of first refusal. 

Mauritius will receive an annual rent of £165 million from the UK for the first three years, followed by £120 million annually for the subsequent ten years. Thereafter, the £120 million annual payment will be adjusted for inflation.<ref>{{Cite web |title=UK Hands Over Control of Chagos Islands to Mauritius |url=https://maritime-executive.com/article/uk-hands-sovereignty-over-diego-garcia-and-chagos-islands-to-mauritius |access-date=2025-05-23 |website=The Maritime Executive |language=en}}</ref>

==Development==
Structures on the islands are located in the joint defence and [[Naval Support Facility Diego Garcia]], although the Plantation house and other structures left behind by the Ilois are still standing, however left abandoned and decaying. Other uninhabited islands, especially in the Salomon Atoll, are common stopping points for long-distance [[Cruising (maritime)|yachtsmen]] travelling from [[Southeast Asia]] to the [[Red Sea]] or the coast of [[Africa]], although a permit is required to visit the outer islands.

== People and language ==
[[File:Diego garcian.jpg|thumb|A [[Chagossians|Chagossian]] photographed by a [[US National Geodetic Survey]] team in 1971]]
{{ anchor |People}}{{ anchor |language}}
=== Chagossians ===
{{see also|Expulsion of the Chagossians}}
The islanders were known as the [[Ilois]] (a French Creole word for {{gloss |islanders}}) and they numbered about 1,000. They were of mixed African, South Indian, Portuguese, English, French and Malay descent and lived very simple, spartan lives in their isolated archipelago working in the coconut and sugar plantations, or in the fishing and small textile industries. Few remains of their culture have been left, although their language is still spoken by some of their descendants in Mauritius.

The inhabitants of Chagos were speaking [[Chagossian Creole]], also known as Ilois creole, a [[French language|French]] [[Creole language|Creole]] which has not been properly researched{{cn |date=May 2025}} from the linguistic point of view.

The island names are a mixture of [[Dutch language|Dutch]], [[French language|French]], [[English language|English]] and [[Ilois|Ilois Creole]].

The Ilois who inhabited the islands were forcibly removed by the US and British governments during the late 1960s and early 1970s{{snd}}effectively turning the islands into a military base. While a number of islanders had petitioned for the return of their former homes and their right to return has been recognised by the UN General Assembly, the International Court of Justice, and the International Tribunal for the Law of the Sea, the US and UK legal systems have refused to adhere to these decisions, leaving the Chagossians in exile.<ref>{{cite web|url=https://www.bbc.com/news/uk-36659976|title=Chagos islanders cannot return home, says Supreme Court|date=29 June 2016|website=Bbc.com|access-date=26 August 2017|archive-date=26 August 2017|archive-url=https://web.archive.org/web/20170826203524/http://www.bbc.com/news/uk-36659976|url-status=live}}</ref>

===Other===
Diego Garcia is currently the only inhabited island in the Chagos, all of which compose the [[British Indian Ocean Territory]], usually abbreviated as BIOT. The UK considers it an [[Overseas territory of the United Kingdom]], and the [[Government of the British Indian Ocean Territory|Government of the BIOT]] consists of a [[Commissioner of the British Indian Ocean Territory|Commissioner]] appointed by [[King Charles III|the King]] on the advice of the [[Foreign and Commonwealth Office]]. The Commissioner is assisted by an Administrator and small staff, and is based in London and resident in the Foreign and Commonwealth Office. This administration is represented in the Territory by the Officer commanding British Forces on Diego Garcia, the ''Brit Rep''. Laws and regulations are promulgated by the Commissioner and enforced in the BIOT by the British Representative.

There are no indigenous peoples living on the island, and the UK represents the Territory internationally. A local government as normally envisioned does not exist.<ref>{{cite web |url=https://www.cia.gov/the-world-factbook/countries/british-indian-ocean-territory/ |work=[[The World Factbook]] |title=British Indian Ocean Territory |publisher=[[Central Intelligence Agency|CIA]] |access-date=2013-10-20 |archive-date=17 January 2021 |archive-url=https://web.archive.org/web/20210117034125/https://www.cia.gov/the-world-factbook/countries/british-indian-ocean-territory/ |url-status=live }}</ref> Around 1,700 armed services personnel and 1,500 civilian contractors, mostly American, are stationed on Diego Garcia.<ref>{{cite web|title=Diego Garcia 'Camp Justice' 7º20'S 72º25'E|url=http://www.globalsecurity.org/military/facility/diego-garcia.htm|website=Global Security.org|access-date=17 July 2014|archive-date=7 December 2010|archive-url=https://web.archive.org/web/20101207193041/http://www.globalsecurity.org/military/facility/diego-garcia.htm|url-status=live}}</ref>

{{As of|2012}}, the islands have a transitory population of about 3,000 including 300 [[United Kingdom|British]] government personnel, 2,700 [[United States Army]], [[United States Navy|Navy]] and [[United States Air Force|Air Force]] personnel.

The Catholics are pastorally served by the [[Roman Catholic Diocese of Port-Louis]], which includes the BIOT.

==Ecology==
{{See also|Chagos Marine Protected Area}}
The Chagos, together with the Maldives and [[Lakshadweep]], forms the [[Maldives–Lakshadweep–Chagos Archipelago tropical moist forests]] [[terrestrial ecoregion]].<ref>{{WWF ecoregion|id=im0125 |name=Maldives-Lakshadweep-Chagos Archipelago tropical moist forests|access-date=2012-06-21}}</ref> The islands and their surrounding waters are a vast oceanic Environment Preservation and Protection Zone (EPPZ) (Fisheries Conservation and Management Zone (FCMZ) of {{convert|544000|km2}}), an area twice the size of the UK's land surface.

The deep oceanic waters around the Chagos Islands, out to the 200 nautical mile limit, include an exceptional diversity of undersea geological features (such as 6000 m deep trenches, oceanic ridges, and sea mounts). These areas almost certainly harbour many undiscovered and specially adapted species. Although the deepwater habitats surrounding the islands have not been explored or mapped in any detail, work elsewhere in the world has shown that high physical diversity of the sea floor is closely linked to a high diversity of species.

The [[biodiversity]] of the Chagos archipelago and its surrounding waters is one of the main reasons it is so special. As of 2010, 76 species that call Chagos home were listed on the [[IUCN Red List of Threatened Species]].<ref name="IUCN1">{{cite web|title=A Marine Protected Area (MPA) in Chagos|url=https://cmsdata.iucn.org/downloads/mpa_chagos___iucn_response_to_fco.pdf|website=IUCN|access-date=2 November 2016|archive-date=27 September 2015|archive-url=https://web.archive.org/web/20150927143052/http://cmsdata.iucn.org/downloads/mpa_chagos___iucn_response_to_fco.pdf|url-status=dead}}</ref>

===Coral===
[[File:Ctenella.jpg|thumb|right|The [[brain coral]] ''[[Ctenella chagius]]'' is endemic to the reefs of the Chagos.]]

The reefs host at least 371 species of coral including the [[endemism|endemic]] [[brain coral]] ''[[Ctenella chagius]]''. Historically, the coral cover was dense and healthy even in deep water on the steep outer reef slopes.<ref>{{Citation|last1=Andradi-Brown|first1=Dominic A.|title=The Chagos Archipelago|date=2019|work=Mesophotic Coral Ecosystems|pages=215–229|editor-last=Loya|editor-first=Yossi|series=Coral Reefs of the World|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-92735-0_12|isbn=9783319927350|last2=Dinesen|first2=Zena|last3=Head|first3=Catherine E. I.|last4=Tickler|first4=David M.|last5=Rowlands|first5=Gwilym|last6=Rogers|first6=Alex D.|s2cid=181769548|editor2-last=Puglise|editor2-first=Kimberly A.|editor3-last=Bridge|editor3-first=Tom C.L.}}</ref> Thick stands of branching [[staghorn coral]] (''Acropora'' sp) previously protected the low-lying islands from wave erosion. Despite the loss of much of the coral in a [[Coral bleaching|bleaching]] event in 1998 the recovery in the Chagos was remarkable and overall coral cover increased year on year to 2014.<ref>{{Cite journal|last1=Lange|first1=Ines D.|last2=Perry|first2=Chris T.|date=2019-08-01|title=Bleaching impacts on carbonate production in the Chagos Archipelago: influence of functional coral groups on carbonate budget trajectories|journal=Coral Reefs|language=en|volume=38|issue=4|pages=619–624|doi=10.1007/s00338-019-01784-x|bibcode=2019CorRe..38..619L|issn=1432-0975|doi-access=free|hdl=10871/36110|hdl-access=free}}</ref> High water temperatures, however, caused coral bleaching in both 2015 and 2016 which resulted in the death of more than two-thirds of corals.<ref>{{Cite journal|last1=Head|first1=Catherine E. I.|last2=Bayley|first2=Daniel T. I.|last3=Rowlands|first3=Gwilym|last4=Roche|first4=Ronan C.|last5=Tickler|first5=David M.|last6=Rogers|first6=Alex D.|last7=Koldewey|first7=Heather|last8=Turner|first8=John R.|last9=Andradi-Brown|first9=Dominic A.|date=2019-07-12|title=Coral bleaching impacts from back-to-back 2015–2016 thermal anomalies in the remote central Indian Ocean|journal=Coral Reefs|volume=38|issue=4|pages=605–618|language=en|doi=10.1007/s00338-019-01821-9|issn=1432-0975|bibcode=2019CorRe..38..605H|doi-access=free}}</ref>

===Fish===

The reefs are also home to at least 784 species of fish that stay near to the shores of the islands including the endemic [[clownfish]] (''[[Amphiprion chagosensis]]'') and many of the larger [[wrasse]] and [[grouper]] that have already been lost from over-fishing in other reefs in the region.<ref>{{Cite journal|last1=SHEPPARD|first1=C. R. C.|last2=Ateweberhan|first2=M.|last3=Bowen |first3=B. W.|last4=Carr |first4=P.|last5=Chen|first5=C. A.|last6=Clubbe |first6=C.|last7=Craig |first7=M. T.|last8=Ebinghaus |first8=R.|last9=Eble |first9=J.|last10=Fitzsimmons |first10=N.|last11=Gaither |first11=M. R.|date=March 2012|title=Reefs and islands of the Chagos Archipelago, Indian Ocean: why it is the world's largest no-take marine protected area|journal=Aquatic Conservation: Marine and Freshwater Ecosystems|volume=22|issue=2|pages=232–261|doi=10.1002/aqc.1248|issn=1052-7613|pmc=4260629|pmid=25505830|bibcode=2012ACMFE..22..232S }}</ref>

As well as the healthy communities of reef fish there are significant populations of pelagic fish such as [[manta ray]]s (''Manta birostris''), [[whale shark]]s, other [[sharks]], and [[tuna]]. Shark numbers have dramatically declined as a result of illegal fishing boats that seek to remove their fins and also as accidental by-catch in the two tuna fisheries that used to operate seasonally in the Chagos.<ref>{{Cite web|title=Sharks Crack The Case: Uncovering Illegal Activities In Paradise|url=https://www.forbes.com/sites/melissacristinamarquez/2019/03/26/sharks-crack-the-case-uncovering-illegal-activities-in-paradise/|last=Márquez|first=Melissa Cristina|website=Forbes|language=en|date=March 26, 2019|access-date=2020-05-30|archive-date=8 November 2020|archive-url=https://web.archive.org/web/20201108000842/https://www.forbes.com/sites/melissacristinamarquez/2019/03/26/sharks-crack-the-case-uncovering-illegal-activities-in-paradise/|url-status=live}}</ref>

===Birds===
[[File:Seabirds nesting on South Brother island in the Chagos Archipelago.jpg|thumb|right|Seabirds nesting on [[South Brother (Chagos Bank)|South Brother island]] in the Chagos Archipelago]]

Seventeen species of breeding [[seabird]] can be found nesting in huge colonies on many of the islands in the archipelago, and 10 of the islands have been designated [[Important Bird Areas]] by [[BirdLife International]]. This means that Chagos has the most diverse breeding seabird community in this tropical region. Of particular interest are the large colonies of sooty terns (''[[Sterna fuscata]]''), brown and lesser noddies (''[[Anous stolidus]]'' and ''[[Anous tenuirostris]]''), wedge-tailed shearwaters (''[[Puffinus pacificus]]'') and [[red-footed boobies]] (''Sula sula'').{{Citation needed|date = March 2015}} Land bird fauna is poor and consists of introduced species and recent natural colonisers. [[Red fody]] has been introduced and is now widespread.

===Mammals===
Environments in the Chagos Archipelago provide rich biodiversity and support varieties of [[cetacean]] species,<ref>{{cite web |url=http://chagos-trust.org/sites/default/files/images/ChagosNews21.pdf |title=Chagos News No. 21 |date=February 2003 |issn=1355-6746 |access-date=2016-03-02 |url-status=dead |archive-url=https://web.archive.org/web/20160316053958/http://chagos-trust.org/sites/default/files/images/ChagosNews21.pdf |archive-date=2016-03-16}}</ref> such as three populations of [[blue whale]]s<ref>Dunne R. P., Polunin N. V., Sand P. H., Johnson M. L., 2014. [https://www.researchgate.net/publication/267746949_The_Creation_of_the_Chagos_Marine_Protected_Area_A_Fisheries_Perspective The Creation of the Chagos Marine Protected Area: A Fisheries Perspective] {{Webarchive|url=https://web.archive.org/web/20180820172620/https://www.researchgate.net/publication/267746949_The_Creation_of_the_Chagos_Marine_Protected_Area_A_Fisheries_Perspective |date=20 August 2018 }}. ''Advances in Marine Biology'' (69). pp. 79–127. [[ResearchGate]].</ref> and [[toothed whale]]s ([[sperm whale|sperm]], [[pilot whale|pilot]], [[orca]], [[false killer whale|pseudo-orca]], [[risso's dolphin|risso's]] and other dolphins such as [[spinner dolphin|spinners]]).<ref>{{cite web|url=http://us.whales.org/blog/2010/02/concerns-about-chagos-archipelago-mpa-proposal|title=Concerns about the Chagos Archipelago MPA Proposal|website=Us.whales.org|access-date=26 August 2017|archive-url=https://web.archive.org/web/20170705135602/http://us.whales.org/blog/2010/02/concerns-about-chagos-archipelago-mpa-proposal|archive-date=5 July 2017|url-status=dead}}</ref> [[Dugong]]s are now locally extinct but once thrived in the archipelago and [[Sea Cow Island]] was named after the presence of the species.<ref>{{cite web|url=http://www.chagos-trust.org/sites/default/files/images/Conservation%20and%20Management%20Plan.pdf|archive-url=https://web.archive.org/web/20121102064723/http://www.chagos-trust.org/sites/default/files/images/Conservation%20and%20Management%20Plan.pdf|url-status=dead|archive-date=2 November 2012|title=Conservation and Management in British Indian Ocean Territory (Chagos Archipelago)|website=Chagos-trust.org|access-date=26 August 2017}}</ref><ref>{{cite web|url=http://www.sealifebase.org/country/CountrySpeciesSummary.php?c_code=826F&Genus=Dugong&Species=dugon|title=Dugong dugon, dugong|website=Sealifebase.org|access-date=26 August 2017|archive-date=4 November 2016|archive-url=https://web.archive.org/web/20161104005251/http://www.sealifebase.org/country/CountrySpeciesSummary.php?c_code=826F&Genus=Dugong&Species=dugon|url-status=live}}</ref> [[Donkey]]s left behind when the Ilois were relocated also roam free.

===Turtles===
The remote islands make perfect undisturbed sites for nests of green (''[[Chelonia mydas]]'') and hawksbill (''[[Eretmochelys imbricata]]'') turtles. The populations of both species in Chagos are of global significance given the [[critically endangered]] status of hawksbills and the [[endangered]] status of [[green turtles]] on the [[IUCN Red List]]. Chagos turtles had been heavily exploited for two centuries but they and their habitats are now well protected by the government of the British Indian Ocean Territory and are recovering well.{{Citation needed|date = March 2015}}

===Crustaceans===
[[File:Coconut Crab on Chagos Archipelago.jpg|thumb|right|[[Coconut crab]]s are the world's largest terrestrial arthropod and live in one of the most undisturbed populations in the Chagos.]]

The [[coconut crab]] (''Birgus latro'') is the world's largest terrestrial [[arthropod]],<ref name="Sheppard2013">{{cite book|author=Charles Sheppard|title=Coral Reefs of the United Kingdom Overseas Territories|url=https://books.google.com/books?id=XQlAAAAAQBAJ&pg=PA278|date=2013|publisher=Springer Science & Business Media|isbn=978-94-007-5965-7|pages=278–}}</ref> reaching more than a metre in leg span and 3.5–4 kilos in weight. As a juvenile it behaves like a hermit crab and uses empty coconut shells as protection, but as an adult this giant crab climbs trees and can crack through a coconut with its massive claws. Despite its wide global distribution, it is rare in most of the areas in which it is found. The coconut crabs on Chagos constitute one of the most undisturbed populations in the world.<ref name="KBS1">{{cite web|title=A Diversity of Decapods|url=https://www.livingoceansfoundation.org/crab-species-chagos-decapod-diversity/|website=Khaled bin Sultan Living Oceans Foundation|date=10 April 2015|access-date=2 November 2016}}</ref><ref name="Areas1991">{{cite book|author=IUCN Commission on National Parks and Protected Areas|title=Protected Areas of the World: Afrotropical|url=https://books.google.com/books?id=GAtfSkr1q6sC&pg=PT341|year=1991|publisher=IUCN|isbn=978-2-8317-0092-2|pages=341–}}</ref> An important part of their biology is the long distances their young can travel as larvae. This means the Chagos coconut crabs are a vital source for replenishing other [[overexploitation|over-exploited]] populations in the Indian Ocean region.{{Citation needed|date = March 2015}}

===Insects===
{{Main|List of Lepidoptera of the Chagos Archipelago}}
113 species of insect have been recorded from the Chagos Islands.{{Citation needed|date = March 2015}}

===Plants===
The Chagos Islands were colonised by plants once there was sufficient soil to support them—probably less than 4,000 years. Seeds and spores arrived on the emerging islands by wind and sea and from passing [[seabird]]s. The native [[flora]] of the Chagos Islands is thought to consist of forty-one species of flowering plant and four [[fern]]s, as well as a wide variety of [[moss]]es, [[Marchantiophyta|liverworts]], [[fungi]] and [[cyanobacteria]].{{Citation needed|date = March 2015}}

Today the status of the Chagos Islands’ native [[flora]] depends very much on past exploitation of particular islands. About 280 species of flowering plant and fern have now been recorded on the islands, but this increase reflects the introduction of non-native plants by humans, either accidentally or deliberately. As some of these non-native species have become invasive and pose a threat to the native ecosystems, plans are being developed to control them. On some islands native forests were felled to plant coconut palms for the production of [[copra oil]]. Other islands remain unspoiled and support a wide range of habitats, including unique ''[[Pisonia]]'' forests and large clumps of the gigantic fish poison tree (''[[Barringtonia asiatica]]''). Unspoiled islands provide us with the biological information that we need to re-establish the native plant communities on heavily altered islands. These efforts will ultimately help to improve the [[biodiversity]] of the Chagos Islands.{{Citation needed|date = March 2015}}

==Conservation efforts==

===Past===
[[File:Sampling work in the Chagos.JPG|thumb|right|Scientist recording coral species for ongoing monitoring work in the archipelago]]
Successive UK governments, both [[Labour Party (United Kingdom)|Labour]] and [[Conservative Party (UK)|Conservative]], have supported environmental conservation of the Chagos. They have committed to treating the whole area as a [[World Heritage Site]]. In 2003 the UK government established an Environment (Protection and Preservation) Zone under Article 75 of the [[UN Convention on the Law of the Sea]] extending 200 [[nautical miles]] from the islands. On eastern [[Diego Garcia]], the largest island of the Chagos and the site of a UK–US military facility,<ref>{{cite web |first=John |last=Pike |url=http://www.globalsecurity.org/military/facility/diego-garcia.htm |title=Diego Garcia 'Camp Justice' |publisher=Globalsecurity.org |access-date=2012-06-21 |archive-date=7 December 2010 |archive-url=https://web.archive.org/web/20101207193041/http://www.globalsecurity.org/military/facility/diego-garcia.htm |url-status=live }}</ref> [[United Kingdom|Britain]] has designated the very large [[lagoon]] and the eastern arm of the atoll and seaward reefs as a "wetland of international importance" under the [[Convention on Wetlands of International Importance]] (the [[Ramsar Convention]]).<ref>{{cite web |url=http://www.unep-wcmc.org/wh/reviews/wetlands/t11.htm |title=Wetland and marine protected areas on the world heritage list |access-date=August 30, 2016}}{{cbignore|bot=medic}}{{dead link|date=July 2014}}</ref>

===Present===
On 1 April 2010 Britain announced the creation of the [[Chagos Marine Protected Area]], the world's largest continuous marine protected reserve, with an area of {{convert|545,000|km2|sqmi|abbr=on}}.<ref name=Eilperin2010>{{Citation
 | last = Eilperin | first = Juliet
 | date = 2 April 2010 | access-date = 4 April 2010
 | title = Britain protects Chagos Islands, creating world's largest marine reserve
 | newspaper = The Washington Post | series = Green
 | url = https://www.washingtonpost.com/wp-dyn/content/article/2010/04/01/AR2010040102894.html
}}</ref><ref name=Rincon2010>{{Citation
 | last = Rincon
 | first = Paul
 | date = 1 April 2010
 | access-date = 7 April 2010
 | title = UK sets up Chagos Islands marine reserve
 | periodical = BBC News
 | url = http://news.bbc.co.uk/1/hi/sci/tech/8599125.stm
 | archive-date = 19 November 2022
 | archive-url = https://web.archive.org/web/20221119052958/http://news.bbc.co.uk/1/hi/sci/tech/8599125.stm
 | url-status = live
 }}</ref><ref>{{Citation
 | date = 1 April 2010 | access-date = 7 April 2010
 | title = New protection for marine life
 | periodical = Foreign & Commonwealth Office
 | url = http://www.fco.gov.uk/en/news/latest-news/?view=News&id=22001512
 | archive-url = http://webarchive.nationalarchives.gov.uk/20121212135632/http://www.fco.gov.uk/en/news/latest-news/?view=News&id=22001512
 | archive-date = 12 December 2012
}}</ref>

This followed an effort led by the Chagos Environment Network,<ref name="protect">{{cite web |url=http://protectchagos.org |title=Welcome to the Chagos Conservation Trust &#124; Chagos Conservation Trust |website=Protectchagos.org |access-date=2012-06-21 |url-status=dead |archive-url=https://web.archive.org/web/20120119044248/http://protectchagos.org/ |archive-date=2012-01-19}}</ref> a collaboration of nine leading conservation and scientific organisations seeking to protect the rich biodiversity of the Chagos Archipelago and its surrounding waters. The Chagos Environment Network cites several reasons for supporting a protected area.

The UK government opened a three-month [[public consultation]], which ended after 5 March 2010, on conservation management of the Chagos Islands and its surrounding waters.<ref name="FCO">{{cite web|url=http://www.fco.gov.uk/resources/en/pdf/21153320/mpa-consultation-101109 |title=Consultation on Whether to Establish a Marine Protected Area in the British Indian Ocean Territory |access-date=2010-02-06 |url-status=dead |archive-url=https://web.archive.org/web/20100206233541/http://www.fco.gov.uk/resources/en/pdf/21153320/mpa-consultation-101109 |archive-date=2010-02-06}}</ref>

On 1 April 2010 the British government [[Cabinet (government)|Cabinet]] established the Chagos Archipelago as the world's largest [[marine reserve]]. At {{cvt|640,000|km2}}, it is larger than both [[France]] and the US state of [[California]]. It doubled the total area of environmental no-take zones worldwide.<ref name="Managing Protected" /> The protection of the marine reserve will be guaranteed for the next five years thanks to the financial support of the [[Ernesto Bertarelli|Bertarelli]] Foundation.<ref>{{cite news |author=PA |url=https://www.independent.co.uk/environment/nature/billionaire-saves-marine-reserve-plans-2077437.html |title=Billionaire saves marine reserve plans |publisher=Independent.co.uk |date=2010-09-12 |access-date=2012-06-21 |location=London |archive-date=9 November 2020 |archive-url=https://web.archive.org/web/20201109033759/http://www.independent.co.uk/environment/nature/billionaire-saves-marine-reserve-plans-2077437.html |url-status=live }}</ref> The setting up of the marine reserve would appear to be an attempt to prevent any repatriation by the inhabitants evicted in the 1960s and 1970s. Leaked US cables have shown the FCO suggesting to its US counterparts that setting up a protected no-take zone would make it "difficult, if not impossible" for the islanders to return. The reserve was then created in 2010.<ref>{{cite news |first1=Rob |last1=Evans |first2=Richard |last2=Norton-Taylor |author-link2=Richard Norton-Taylor |url=https://www.theguardian.com/politics/2010/dec/03/wikileaks-cables-diego-garcia-uk |title=WikiLeaks: Foreign Office accused of misleading public over Diego Garcia |newspaper=[[The Guardian]] |date=4 December 2010 |access-date=2013-10-20 |location=[[London]] |archive-date=7 July 2015 |archive-url=https://web.archive.org/web/20150707111552/http://www.theguardian.com/politics/2010/dec/03/wikileaks-cables-diego-garcia-uk |url-status=live }}</ref>

====Permanent Court of Arbitration ruling====
On 18 March 2015 the [[Permanent Court of Arbitration]] unanimously held that the [[Chagos Marine Protected Area|marine protected area]] (MPA) that the UK had declared around the Chagos Archipelago in April 2010 violated international law. [[Anerood Jugnauth]], [[Prime Minister of Mauritius]], pointed out that it was the first time that the UK's conduct with regard to the Chagos Archipelago had been considered and condemned by any international court or tribunal. He qualified the ruling as an important milestone in the relentless struggle, at the political, diplomatic and other levels, of successive governments over the years for the effective exercise by Mauritius of its sovereignty over the Chagos Archipelago. The tribunal considered in detail the undertakings given by the United Kingdom to the Mauritian ministers at the Lancaster House talks in September 1965. The UK had argued that those undertakings were not binding and had no status in international law. The tribunal firmly rejected that argument, holding that the undertakings became a binding international agreement upon the independence of Mauritius and had bound the UK ever since. It found that the UK's commitments towards Mauritius in relation to fishing rights and oil and mineral rights in the Chagos Archipelago were legally binding. The Tribunal also found that the United Kingdom's undertaking to return the Chagos Archipelago to Mauritius when no longer needed for defence purposes was legally binding. This establishes that, in international law, Mauritius has real, firm and binding rights over the Chagos Archipelago and that the United Kingdom must respect those rights. The tribunal went on to hold that the United Kingdom had not respected Mauritius’ binding legal rights over the Chagos Archipelago. It considered the events from February 2009 to April 2010, during which time the MPA proposal came into being and was then imposed on Mauritius.<ref name="alla">{{cite web | url=http://allafrica.com/stories/201503231218.html | title=Mauritius: MPA Around Chagos Archipelago Violates International Law – This Is a Historic Ruling for Mauritius, Says PM | website=Allafrica.com/ | access-date=23 March 2015 | archive-date=11 September 2016 | archive-url=https://web.archive.org/web/20160911131000/http://allafrica.com/stories/201503231218.html | url-status=live }}</ref><ref name="govmu.org">{{cite web | url=http://www.govmu.org/English/News/Pages/MPA-around-Chagos-Archipelago-violates-international-law-%E2%80%93-This-is-a-Historic-ruling-for-Mauritius,-says-PM.aspx | title=MPA around Chagos Archipelago violates international law – This is a Historic ruling for Mauritius, says PM | publisher=[[Government Portal of Mauritius]] | date=23 March 2015 | access-date=24 March 2015 | archive-date=26 March 2015 | archive-url=https://web.archive.org/web/20150326033444/http://www.govmu.org/English/News/Pages/MPA-around-Chagos-Archipelago-violates-international-law-%E2%80%93-This-is-a-Historic-ruling-for-Mauritius,-says-PM.aspx | url-status=live }}</ref>

====WikiLeaks cablegate disclosure ====
According to [[United States diplomatic cables leak|United States diplomatic cables]] published by [[WikiLeaks]], the UK and US wanted to safeguard the strategic value of the Chagos Islands.

WikiLeaks published a cable from the US embassy in London to Washington stating:<ref name="welz2022">{{cite journal |last1=Welz |first1=Martin |title=The Chagos Islands and international orders: human rights, rule of law, and foreign rule |journal=International Relations |date=5 November 2022 |doi=10.1177/00471178221136 |doi-broken-date=10 November 2024 |url=https://journals.sagepub.com/doi/full/10.1177/00471178221136015#body-ref-fn52-00471178221136015 |access-date=15 November 2023}}</ref>
{{blockquote |text=HMG would like to establish a marine park or reserve providing comprehensive environmental protection to the reefs and waters of the British Indian Ocean Territory (BIOT), a senior Foreign and Commonwealth Office (FCO) official informed Polcouns on May 12. The official insisted that the establishment of a marine park—the world's largest—would in no way impinge on USG use of the BIOT, including Diego Garcia, for military purposes. He agreed that the UK and US should carefully negotiate the details of the marine reserve to assure that US interests were safeguarded and the strategic value of BIOT was upheld. He said that the BIOT's former inhabitants would find it difficult, if not impossible, to pursue their claim for resettlement on the islands if the entire Chagos Archipelago were a marine reserve.}}

==See also==
* [[List of islands in the Chagos Archipelago]]
* [[Chagos Archipelago sovereignty dispute]]
* [[Expulsion of the Chagossians]]
* [[Great Chagos Bank]]
* [[Chagos Marine Protected Area]]
* [[Depopulation of Diego Garcia]]
* [[List of island countries and territories in the Indian Ocean]]
* [[British Indian Ocean Territory]]
* [[Indian Ocean]]
* [[Scattered Islands in the Indian Ocean|Scattered Islands]]
* [[Naval Support Facility Diego Garcia]]

==References==
{{Reflist |30em}}

==Further reading==
{{Refbegin |30em}}
*{{cite book |last=Pilger |first=John |year=2006 |chapter=Chapter 1: Stealing a Nation |pages=19–60 |title=Freedom Next Time |publisher=Bantam Press |isbn=0-593-05552-7 |url=https://archive.org/details/freedomnexttime0000pilg |url-access=registration }}
*{{cite book |first=Philippe |last=Sands |author-link=Philippe Sands |year=2022 |title=The Last Colony: A Tale of Exile, Justice and Britain's Colonial Legacy |publisher=[[Weidenfeld & Nicolson]] |isbn=978-1-4746-1812-0 }}
*{{cite book |first=Philippe |last=Sands |author-link=Philippe Sands |year=2023 |title=The Last Colony: A Tale of Exile, Justice, and Courage |publisher=[[Alfred A. Knopf]] |isbn=9780593535097 }}
*{{cite magazine |last=Rao |first=Padma |date=2005-12-05 |title=Der Edikt der Königin |language=de |magazine=Der Spiegel |pages=152–154 }}
*{{cite book |last=Romero-Frias |first=Xavier |author-link=Xavier Romero-Frias |year=1999 |title=The Maldive Islanders, A Study of the Popular Culture of an Ancient Ocean Kingdom |publisher=Nova Ethnographia Indica |location=Barcelona |isbn=84-7254-801-5 }}
*{{cite book |last=Vine |first=David |year=2009 |title=Island of Shame: The Secret History of the US Military Base on Diego Garcia |publisher=Princeton University Press |isbn=978-0-691-13869-5 }}
*{{cite book |last1=Wenban-Smith |first1=N. |last2=Carter |first2=M. |year=2016 |title=Chagos: A History, Exploration, Exploitation, Expulsion |publisher=Chagos Conservation Trust |location=London |isbn=978-0-9954596-0-1 }}
{{Refend}}

==Novels==
{{Refbegin |30em}}
* [[Shenaz Patel]], ''Le silence des Chagos'', [[Éditions de l'Olivier]], 2005, {{ISBN|9782879294544}}
* Caroline Laurent, ''Rivage de la colère'', Les Escales, 2020, {{ISBN|9782266311915}}
{{Refend}}

==External links==
*[https://www.gov.uk/government/publications/ukmauritius-agreement-concerning-the-chagos-archipelago-including-diego-garcia-cs-mauritius-no12025 UK/Mauritius: Agreement concerning the Chagos Archipelago including Diego Garcia]
* [https://www.icj-cij.org/en/case/169 ICJ Advisory Opinion 2019: Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965]
* [https://www.chagossupport.org.uk/ Chagos | UK Chagos Support Association]
* [http://www.chagosfilm.com/ Chagos: A Documentary Film]
* [https://permanent.access.gpo.gov/websites/pollux/pollux.nss.nima.mil/NAV_PUBS/SD/pub171/171sec08.pdf Indian Ocean Pilot: Sector 8. The Seychelles Islands to the Chagos Archipelago (U.S Government Publishing Office)]
* [https://govmu.org/EN/Pages/AboutChagos.aspx About Chagos Archipelago in Governenment of Mauritius website]

{{Subject bar |auto=y |portal1=Mauritius |portal2=Geography }}
{{Atolls of the Chagos Archipelago}}
{{Authority control}}

[[Category:Chagos Archipelago| ]]
[[Category:Archipelagoes of Mauritius]]
[[Category:Archipelagoes of the Indian Ocean]]
[[Category:Archipelagoes of the Maldives]]
[[Category:Archipelagoes of the United Kingdom]]
[[Category:Disputed islands of Asia]]
[[Category:Geography of the British Indian Ocean Territory]]
[[Category:Western Indo-Pacific]]
[[Category:Lists of coordinates]]