History of Diego Garcia in Timeline

Diego Garcia, the largest island in the Chagos Archipelago, is a British overseas territory and site of a joint UK–U.S. military base since the 1970s. The Chagossians were controversially expelled to establish the base. While a treaty signed in 2025 intends to transfer sovereignty to Mauritius, the military base is slated to remain under British control for at least 99 years, potentially longer. This agreement has drawn criticism, including "deep concern" from the UN Committee on the Elimination of Racial Discrimination.

1905: Botanical observations and collections during the plantation era

In 1905, botanical studies and collections were conducted on Diego Garcia during the plantation era, contributing to the understanding of the island's vegetation at that time.

1939: Botanical observations and collections during the plantation era

In 1939, botanical studies and collections were conducted on Diego Garcia during the plantation era, contributing to the understanding of the island's vegetation at that time.

September 1944: Wreck of a Royal Air Force PBY Catalina

On 16 September 1944, a storm caused the wreck of a Royal Air Force PBY Catalina on Diego Garcia.

November 1965: UK purchased the Chagos Archipelago

In November 1965, the UK purchased the Chagos Archipelago, including Diego Garcia, from Mauritius for £3 million to create the British Indian Ocean Territory (BIOT).

1965: Administered from Mauritius

From 1814 to 1965 Diego Garcia was administered from Mauritius; the main plantations were at East Point, the main settlement, Minni Minni, 4.5 km north of East Point, and Pointe Marianne, on the western rim, all on the lagoon side of the atoll.

1965: Island becomes part of British Indian Ocean Territory

In 1965, Diego Garcia became part of the newly formed British Indian Ocean Territory, having previously been part of Mauritius.

1965: Islands legally separated from Mauritius

In February 2019, the ICJ in The Hague ruled that the United Kingdom must transfer the islands to Mauritius as they were not legally separated from the latter in 1965.

April 1966: British Government buys Chagos Agalega Company assets

In April 1966, the British government bought the entire assets of the Chagos Agalega Company in the BIOT for £600,000 and administered them as a government enterprise.

December 1966: US and UK execute agreement for US to use BIOT for defense purposes

On 30 December 1966, the United States and the UK executed an agreement which permitted the United States to use the BIOT for defense purposes for 50 years until December 2016, followed by a 20-year extension (to 2036).

1966: UK/United States Exchange of Notes signed

In 1966, the UK/United States Exchange of Notes was signed, requiring the depopulation of Diego Garcia for the United States to construct a base upon it. This led to the resettlement of inhabitants.

1967: Description of the land area

In 1967, Stoddart described the land area of Diego Garcia as having a littoral hedge of Scaevola taccada, while inland, Cocos nucifera (coconut) was the most dominant tree.

1967: Botanical observations and collections during the plantation era

In 1967, botanical studies and collections were conducted on Diego Garcia during the plantation era, contributing to the understanding of the island's vegetation at that time.

1967: Smithsonian publishes survey

In 1967, the Smithsonian survey was published and used as an authoritative baseline for more recent research on the vegetation of Diego Garcia.

1967: Company terminated the lease at the end of 1967

the company terminated the lease at the end of 1967.

October 1971: Closure of Plantations and Forced Relocation

In October 1971, the plantations on Diego Garcia were closed, and the inhabitants were forcibly relocated, marking the end of the island's colonial period.

1971: Military Personnel and Civilian Employees as Residents

Between 1971 and 2001, the only residents on Diego Garcia were British and American military personnel and civilian employees, including contract employees from the Philippines and Mauritius.

1971: Forcible Resettlement of Diego Garcia Inhabitants

By 1971, all inhabitants of Diego Garcia were forcibly resettled to other islands due to the UK/United States Exchange of Notes signed in 1966 for the construction of a US base. This led to the depopulation of the island.

1971: Diversity in Diego Garcia's Inhabitants

Diego Garcia, through the period 1793–1971, was inhabited by a diverse group of people, including plantation workers, Franco-Mauritian managers, Indo-Mauritian administrators, Mauritian and Seychellois contract employees, and, in the late 19th century, Chinese and Somali employees.

1971: United States Navy LSTs provided consumable food and equipment

From 1971 to 1973, United States Navy LSTs provided consumable food and equipment to Diego Garcia.

1971: Extermination of feral dogs ordered

In 1971, the BIOT Commissioner ordered the extermination of feral dogs on Diego Garcia following the departure of the last plantation workers.

1971: Dredging of Channel and Anchorage Areas

Prior to 1971, the channel and anchorage areas in the northern half of the lagoon were dredged, along with the ship turning basin.

1972: Agreement on Compensation Payments for Exiled Îlois

In 1972, the UK and Mauritian governments agreed that 426 families, totaling 1,151 individuals, were due compensation payments as exiled Îlois.

1972: Donkey population

In 1972, the population of donkeys on Diego Garcia numbered over 400.

1973: Civilian ships contracted to provide consumable food and equipment

Beginning in 1973, civilian ships were contracted to provide consumable food and equipment to Diego Garcia.

1975: Last feral dog observed and shot

In 1975, the program to exterminate feral dogs on Diego Garcia continued, and the last feral dog was observed and shot.

1982: Certification of Îlois by Mauritian Government

In 1982, the Mauritian Government's Îlois Trust Fund Board certified 1,579 people as Îlois.

November 1983: Earthquake measuring 7.6 on the Richter Scale

On 30 November 1983, an earthquake measuring 7.6 on the Richter Scale hit Diego Garcia at 11:46 pm local time, lasting 72 seconds and resulting in minor damage, including wave damage to a 50-metre stretch of the southern end of the island.

September 1990: Demolition of Tent City during Operation Desert Storm

In September 1990, a storm demolished the tent city being constructed for United States Air Force bomber crews during Operation Desert Storm.

1993: J. M. W. Topp collected data annually

Between 1993 and 2003, J. M. W. Topp collected data annually and found that on average, three new plant species arrived each year, mainly on Diego Garcia. This research added a third more species to Stoddart.

1995: Last horse observed

In 1995, the last horse was observed on Diego Garcia.

1995: New species recorded

Since 1995, 32 new species were recorded on Diego Garcia, indicating a very rapid rate of introduction. These species are classified as "weedy" or "naturalized alien species".

1996: Scientific Expedition in Diego Garcia

In 1996, a scientific expedition described the lagoon and surrounding waters of Diego Garcia as "exceptionally unpolluted".

1997: Vegetation survey identified about 280 species of terrestrial vascular plants

In 1997, the United States Navy contracted a vegetation survey that identified about 280 species of terrestrial vascular plants on Diego Garcia. None of these was endemic.

2001: Allied Militaries Based on Diego Garcia

From 2001 to 2006, during combat operations against Afghanistan, allied militaries including Australian, Japanese, and the Republic of Korea were based on Diego Garcia.

2001: Naval exercises between the United States and Indian navies

In 2001, Diego Garcia was the site of several naval exercises between the United States and Indian navies.

2001: COMPSRON 2 consisted of ships

Prior to 2001, COMPSRON 2 on Diego Garcia consisted of up to 20 ships, including four Combat Force Ships which provided rapid-response delivery of equipment to ground troops in the United States Army.

December 2002: Earthquake on Diego Garcia

On 2 December 2002, an earthquake measuring 4.6 on the Richter scale struck Diego Garcia at 12:21 am.

2002: Alleged Imprisonment and Interrogation on Diego Garcia

In 2002, the United States allegedly imprisoned and interrogated at least one suspect on Diego Garcia, as claimed by an unnamed former White House official.

2002: Extraordinary Rendition Flights Refueled on Diego Garcia

In 2002, two United States extraordinary rendition flights refueled on Diego Garcia, as admitted by British Foreign Secretary David Miliband in 2008.

2003: J. M. W. Topp collected data annually

2003: Allied Militaries Based on Diego Garcia for Operations against Iraq

From 2003 to 2006, during combat operations against Iraq, allied militaries including Australian, Japanese, and the Republic of Korea were based on Diego Garcia.

2003: Alleged Imprisonment and Interrogation on Diego Garcia

In 2003, there were allegations of imprisonment and interrogation of at least one suspect on Diego Garcia, according to an unnamed former White House official.

June 2004: Authorities Deny Detainees Passed Through Diego Garcia

In June 2004, British Foreign Secretary Jack Straw stated that United States authorities had repeatedly assured him that no detainees had passed in transit through Diego Garcia or were disembarked there.

December 2004: Tsunami Causes Minor Shoreline Erosion

In December 2004, a tsunami generated near Indonesia caused minor shoreline erosion on Barton Point, the northeast point of Diego Garcia.

2004: MV Baffin Strait began deliveries

From 2004 to 2009, the U.S.-flagged container ship MV Baffin Strait, often referred to as the "DGAR shuttle", delivered 250 containers every month from Singapore to Diego Garcia.

2004: 10 plant communities recognised

In 2004, 10 plant communities were recognized on the atoll rim of Diego Garcia.

2004: Tsunami caused by Indian Ocean earthquake

In 2004, Diego Garcia was somewhat affected by the tsunami caused by the Indian Ocean earthquake. Service personnel reported a minor increase in wave activity. The island was protected by its ocean topography, including the Chagos Trench and coral reefs.

2004: Naval exercises between the United States and Indian navies

In 2004, Diego Garcia was the site of several naval exercises between the United States and Indian navies.

2004: TransAtlantic Lines outbid Sealift Incorporated

In 2004, TransAtlantic Lines outbid Sealift Incorporated for the transport contract between Singapore and Diego Garcia.

2004: U.S. Navy Recruitment

In 2004, U.S. Navy recruitment literature described Diego Garcia as one of the world's best-kept secrets, highlighting great recreational facilities, natural beauty, and outstanding living conditions.

2004: Application for Ramsar Site Wetlands Conservation Status

In 2004, the UK applied to obtain Ramsar site wetlands conservation status for much of the lagoon and other waters of Diego Garcia. Large parts of the island are nature preserves.

January 2005: Baffin Straits charter ran

The Baffin Straits charter on Diego Garcia ran from 10 January 2005, to 30 September 2008, at a daily rate of $12,550.

September 2005: Naval Security Group detachment disestablished

On 30 September 2005, the Naval Security Group detachment on Diego Garcia was disestablished, and remaining essential operations were transferred to a contractor.

2005: Mammal populations

By 2005, the donkey population on Diego Garcia was down to just 20 individuals. Just two cats were thought to have survived an island-wide eradication program.

2005: Rumors of CIA Black Sites on Diego Garcia

In 2005, Diego Garcia was rumored to be one of the locations of the CIA's black sites.

2005: Survey identified just 36 species as "native"

In 2005, a survey identified just 36 species as "native" on Diego Garcia, meaning arriving without the assistance of humans, and found elsewhere in the world. No terrestrial plant species are of any conservation-related concern at present.

2005: Biological survey indicated erosional effects of the tsunami wave

In early 2005, a biological survey indicated erosional effects of the tsunami wave on Diego Garcia and other islands of the Chagos Archipelago. A stretch of shoreline was breached, and shoreline shrubs and coconut palms were washed away.

July 2006: Camp Justice renamed to Camp Thunder Cove

In July 2006, the United States military facilities on Diego Garcia, known informally as Camp Justice, were renamed to Camp Thunder Cove.

2006: Presence of Allied Militaries on Diego Garcia during Combat Operations

From 2001 to 2006, during combat operations against Afghanistan, and from 2003 to 2006 against Iraq, allied militaries including Australian, Japanese, and the Republic of Korea were based on Diego Garcia.

2006: Scientific Expedition in Diego Garcia

In 2006, a scientific expedition described the lagoon and surrounding waters of Diego Garcia as "pristine".

2006: Gunships participated in Ethiopia's invasion of Somalia

In late 2006, American gunships based off Diego Garcia participated in Ethiopia's invasion of Somalia.

June 2007: Allegations of Prisoner Transport Through Diego Garcia

In June 2007, allegations that the military base on Diego Garcia was used for transport of prisoners involved in the extraordinary rendition program were formally reported to the Council of Europe.

July 2007: Storm Hits Diego Garcia

On 22 July 2007, a storm hit Diego Garcia, with winds exceeding 60 knots (69 mph; 110 km/h) and over 250 mm (10 in) of rain falling in 24 hours.

October 2007: Investigation of Prison Camp Allegations Launched

In October 2007, the Foreign Affairs Select Committee of the British Parliament announced it would launch an investigation into allegations of a prison camp on Diego Garcia.

February 2008: Admission of Extraordinary Rendition Flights Refueling on Diego Garcia

On 21 February 2008, British Foreign Secretary David Miliband admitted that two United States extraordinary rendition flights refueled on Diego Garcia in 2002 and expressed regret for earlier denials.

July 2008: Allegation of Imprisonment and Interrogation on Diego Garcia

On 31 July 2008, an unnamed former White House official alleged that the United States had imprisoned and interrogated at least one suspect on Diego Garcia during 2002 and possibly 2003.

September 2008: Baffin Straits charter ended

The Baffin Straits charter on Diego Garcia ran from 10 January 2005, to 30 September 2008, at a daily rate of $12,550.

2009: MV Baffin Strait delivered last supplies

From 2004 to 2009, the U.S.-flagged container ship MV Baffin Strait, often referred to as the "DGAR shuttle", delivered 250 containers every month from Singapore to Diego Garcia. In 2009 the service ended.

2009: Checklist of vegetation

In 2009, Topp and Martin Hamilton of Kew Gardens compiled the most recent checklist of vegetation on Diego Garcia.

2009: UK Proposed Marine Reserve to Prevent Return of Former Inhabitants

In 2009, the UK proposed that the BIOT become a "marine reserve" to prevent the former inhabitants from returning to the islands.

August 2010: Ship Composition of MPSRON TWO

In August 2010 the ship composition of MPSRON TWO on Diego Garcia was recorded. The composition is dynamic.

2010: CDAA remains

In 2010, the large AN/AX-16 High Frequency Radio direction finding Circularly Disposed Antenna Array had been demolished, but multiple CDAAs on the island still existed, as seen in satellite imagery.

December 2014: Start of two-year window to give notice of termination of agreement

On 30 December 1966, the United States and the UK executed an agreement through an Exchange of Notes which permitted the United States to use the BIOT for defence purposes for 50 years until December 2016, followed by a 20-year extension (to 2036) as long as neither party gave notice of termination in a two-year window (December 2014 – December 2016).

2015: Diego Garcia Allegedly Used for Nefarious Activities

In 2015, Lawrence Wilkerson, former chief of staff to U.S. Secretary of State Colin Powell, stated that Diego Garcia was allegedly used by the CIA for "nefarious activities", specifically as a transit site for temporary housing and interrogation.

December 2016: End of initial 50-year agreement between US and UK

In December 1966, the United States and the UK executed an agreement which permitted the United States to use the BIOT for defense purposes for 50 years until December 2016, followed by a 20-year extension (to 2036).

2016: Ongoing Litigation and Impoverishment of Chagossians

As of 2016, the British expulsion action remained in litigation. Chagossians who received compensation from the British 15 years after the expulsion, totaling $6,000 per person, remained highly impoverished and marginalized on Mauritius and the Seychelles.

2016: Discussions regarding the importance of the joint base

In May 2019, the United Nations General Assembly affirmed the decision of the International Court of Justice and demanded that the United Kingdom withdraw its colonial administration from the Islands and cooperate with Mauritius to facilitate the resettlement of Mauritian nationals in the archipelago. In a written statement, the U.S. government said that neither the Americans nor the British have any plans to discontinue use of the military base on Diego Garcia. The statement said in a footnote: "In 2016, there were discussions between the United Kingdom and the United States concerning the continuing importance of the joint base. Neither party gave notice to terminate and the agreement remains in force until 2036".

February 2019: ICJ rules UK must transfer islands to Mauritius

In February 2019, the International Court of Justice (ICJ) in The Hague ruled that the United Kingdom must transfer the islands to Mauritius, stating they were not legally separated from Mauritius in 1965.

May 2019: UN General Assembly demands UK withdraw from the Islands

In May 2019, the United Nations General Assembly affirmed the ICJ's decision and demanded that the United Kingdom withdraw its colonial administration from the Islands.

February 2021: Expected completion of radomes

By February 2021, it was expected that Black Construction/Mace International JV would complete two new 13-metre radomes on Diego Garcia, supporting US military activities.

April 2021: Expected completion of antenna facility

By April 2021, it was expected that Black Construction/Mace International JV would complete a 34-metre antenna facility on Diego Garcia, supporting US military activities.

October 2021: Asylum Seekers on Diego Garcia

Since October 2021, there have been asylum seekers on Diego Garcia.

September 2022: Expected completion of power line project

By September 2022, it was expected that SJC-BVIL would complete moving underground the overhead power and telephone lines that run from the Navy ammunition area to the Air Force ammunition area along DG1 on Diego Garcia, supporting US military activities.

November 2022: UK and Mauritius to Negotiate Sovereignty

On 3 November 2022, the British Foreign Secretary announced that the UK and Mauritius had decided to begin negotiations on sovereignty over the British Indian Ocean Territory, ensuring the continued operation of the joint UK/US military base on Diego Garcia.

2022: Underwater fibre-optic cable spur constructed

In 2022, an underwater fibre-optic cable spur from the Oman Australia Cable was constructed to Diego Garcia.

July 2023: Underwater fibre-optic cable spur confirmed

In July 2023, Reuters confirmed an underwater fibre-optic cable spur from the Oman Australia Cable was constructed to Diego Garcia during 2022.

October 2024: UK to hand over the Chagos islands to Mauritius

On 3 October 2024, the UK prime minister Keir Starmer announced that the UK will hand over the Chagos islands to Mauritius.

April 2025: New administration approved letting treaty negotiations continue.

On 1 April 2025, the new administration approved letting treaty negotiations continue.

May 2025: Sovereignty of Chagos Archipelago returned to Mauritius, but Diego Garcia administered by the United Kingdom

In May 2025, an agreement signed by the United Kingdom and Mauritius stipulated that sovereignty of the Chagos Archipelago would be returned to Mauritius. However, Diego Garcia would continue to be administered by the United Kingdom for at least 99 years.

May 2025: UK-Mauritius Agreement signed, granting administrative rights over Diego Garcia to the UK

In May 2025, under the UK-Mauritius Agreement, Mauritius was to have sovereignty over the Chagos Archipelago, including Diego Garcia. The United Kingdom was granted administrative rights over Diego Garcia to maintain its military bases for at least 99 years, while being responsible for the defense and security of the island. Exiled Chagossians and their descendants are not permitted to return to the island.

May 2025: Sovereignty of Chagos Islands transferred to Mauritius

On 22 May 2025, a formal agreement was signed transferring the sovereignty of the Chagos Islands to Mauritius. However, Diego Garcia and its surrounding buffer zone were immediately leased back to the UK, allowing the British-American base to continue operating for 99 years, with potential extensions.

June 2025: British Conservatives Assert High Costs of Restitution Agreement

In June 2025, British Conservatives claimed that the restitution agreement regarding the Chagos Archipelago would cost British taxpayers more than initially anticipated.

January 2026: Trump administration reverses approval of transfer

In January 2026, the Trump administration reversed their previous approval of the transfer of Diego Garcia to Mauritius. Donald Trump criticized the planned transfer by the UK on Truth Social, calling it an act of "GREAT STUPIDITY".

2036: End of 20-year extension to US-UK agreement

2036: Agreement remains in force until 2036

In a written statement in May 2019, the U.S. government said that neither the Americans nor the British have any plans to discontinue use of the military base on Diego Garcia. The statement said in a footnote: "In 2016, there were discussions between the United Kingdom and the United States concerning the continuing importance of the joint base. Neither party gave notice to terminate and the agreement remains in force until 2036".