Tristan da Cunha (pronounced /ˈtrɪstən də ˈkuːnə/) is a remote volcanic group of islands in the south Atlantic Ocean, and also the name of the main island of that group. It is the most remote inhabited archipelago in the world, lying 2,816 kilometres (1,750 mi) from the nearest land, South Africa, and 3,360 kilometres (2,090 mi) from South America. It is part of the British overseas territory of Saint Helena, Ascension and Tristan da Cunha which also includes Saint Helena 2,430 kilometres (1,510 mi) to its north, and equatorial Ascension Island even farther removed, grouping the British South Atlantic islands into one far-flung centrally administered aggregate. Tristan da Cunha is said to be the "most remote inhabited location on Earth." It has a population of 275 (2009 figures).
The territory consists of the main island of Tristan da Cunha itself, which measures about 11.27 kilometres (7.00 mi) across and has an area of 98 square kilometres (38 sq mi), along with the uninhabited Nightingale Islands and the wildlife reserves of Inaccessible Island and Gough Island.---------The islands were first sighted in 1506 by Portuguese explorer Tristão da Cunha, although rough seas prevented a landing. He named the main island after himself, Ilha de Tristão da Cunha, which was later anglicised to Tristan da Cunha Island.
The first survey of the archipelago was made by the French frigate L'Heure du Berger in 1767. Soundings were taken and a rough survey of the coastline was made. The presence of water at the large waterfall of Big Watron and in a lake on the north coast were noted, and the results of the survey were published by a Royal Navy hydrographer in 1781. The first permanent settler was Jonathan Lambert, from Salem, Massachusetts, United States, who arrived at the islands in December 1810. He declared the islands his property and named them the Islands of Refreshment. Lambert's rule was short-lived, as he died in a boating accident in 1812.-------In 1816 the United Kingdom formally annexed the islands, ruling them from the Cape Colony in South Africa. This is reported to have primarily been a measure to ensure that the French would not be able to use the islands as a base for a rescue operation to free Napoleon Bonaparte from his prison on Saint Helena. The occupation also prevented the United States from using Tristan da Cunha as a base, as they had during the War of 1812. Attempts to colonise Inaccessible Island failed.
The islands were occupied by a garrison of British Marines, and a civilian population was gradually built up. Whalers also set up on the islands as a base for operations in the Southern Atlantic. However, the opening of the Suez Canal in 1869, together with the gradual move from sailing ships to coal-fired steam ships, increased the isolation of the islands, as they were no longer needed as a stopping port for journeys from Europe to the Far East.
In 1867, Prince Alfred, Duke of Edinburgh and second son of Queen Victoria, visited the islands. The main settlement, Edinburgh of the Seven Seas, was named in honour of his visit. Lewis Carroll's youngest brother, the Rev. Edwin H. Dodgson, served as an Anglican missionary and school teacher in Tristan da Cunha in the 1880s. The second Duke of Edinburgh, the husband of Queen Elizabeth II, visited the islands in 1957 as part of a world tour onboard the royal yacht Britannia.------On 12 January 1938, by Letters Patent, the islands were declared a dependency of Saint Helena. Prior to this, passing ships stopped irregularly at the island for a period of mere hours.
During World War II, the islands were used as a top secret Royal Navy weather and radio station codenamed HMS Atlantic Isle, to monitor U Boats (which needed to surface to maintain radio contact) and German shipping movements in the South Atlantic Ocean. The only currency in use on the island at this time was the potato, and islanders labouring to construct the station were paid in kind with naval supplies for their own use, such as wood, paint and tea. Money was introduced the following year, as was the island's first newspaper, The Tristan Times. The first Administrator was appointed by the British Government during this time.
-----In 1958, as part of Operation Argus, the United States Navy exploded an atomic bomb 200 kilometres high in the upper atmosphere, 115 kilometres southeast of the main island.
In 1961, a volcanic eruption forced the evacuation of the entire population to wooden huts in the disused Pendell Army Camp in Merstham, Surrey, England before moving to a more permanent site at a former Royal Air Force station in Calshot near Southampton, England, living mainly in a road called Tristan Close. In 1962, a Royal Society expedition went to the islands to assess the damage, and reported that the settlement Edinburgh of the Seven Seas had been only marginally affected. Most families returned in 1963 led by Willie Repetto (head of the ten-person island council) and Allan Crawford (the former island welfare officer).----In 2005, the islands were given a United Kingdom post code (TDCU 1ZZ) to make it easier for the residents to order goods online.The St Helena, Ascension and Tristan da Cunha Constitution Order 2009 was made by HM the Queen and the Privy Council on 8 July and is expected to come into operation shortly thereafter. The new Constitution replaces the 1988 version and among other changes limits the Governor's powers, includes a Bill of Rights, establishes independence of the judiciary and the public service and formally designates the Governor of St Helena as, concurrently, the Governor for Ascension and Tristan da Cunha. It also ends the "dependency" status of Ascension and Tristan da Cunha on St Helena.