St Helena, Ascension, Tristan da Cunha profiles
St Helena and its dependencies - Ascension Island and Tristan da Cunha - are remote islands about midway between Africa and South America in the South Atlantic Ocean.
Though far from each other, they form a single territorial grouping under the sovereignty of the British Crown. Apart from Ascension, the islands are only accessible by sea.
St Helena is probably best known as the island to which French emperor Napoleon Bonaparte was exiled in 1815 after his defeat at Waterloo. The Zulu Chief, Dinizulu, was confined to St Helena in 1890 and up to 6,000 Boer prisoners were held there after the South African war of 1899-1902.
After being discovered by the Portuguese in 1502, St Helena became a busy way station for sea farers up until the late 1800s when steam started replacing sail, and the opening of the Suez Canal changed the pattern of sea routes.
Its fortunes, however, have declined and several of its residents have left. But the British government hopes to reverse the trend and help the island become self-sufficient by making it accessible by air and therefore more attractive to tourists.
The plan is for an airport to be completed in 2016. The (Royal Mail Ship) RMS St Helena is currently the only public form of access to the island.
Ascension Island, a desert island situated just south of the equator, is a vital staging post for Britain in the South Atlantic. Being about half way between Britain and the Falklands, it served as a key logistical base for troops heading for the Falklands war in 1982.
Ascension was an important communications and operations centre during both World Wars and its Wideawake Airfield is now shared by the British and American air forces.
The island has a transient population of about 1,000, mainly Britons, Americans and St Helenians involved in the military, telecommunications and satellite tracking. It can be reached by air or by the RMS St Helena.
Britain has expressed the intention of applying to the UN to extend its territorial rights around Ascension Island on the grounds that the island's landmass actually reaches much further underwater.
This would give Britain more extensive rights over any oil or gas reserves in the areas.
Tristan da Cunha was at one time on the main trading route between Europe and the Indian Ocean, but the small community living there is now extremely isolated.
It is situated 2,800 km west of Cape Town, South Africa, and is part of a group of islands which includes Inaccessible, Nightingale, Middle, Stoltenhoff, and Gough - which has a manned weather station.
Although Tristan da Cunha was discovered in 1506, it remained uninhabited until it was used by US whalers in the late 1700s. The British navy stationed a garrison there during Napoleon's exile on St Helena, and when the garrison was withdrawn, three men stayed behind and became the founders of the present settlement.
According to Tristan da Cunha's official website the island "was ignored by early explorers as a possible home due to its rugged mountain landscape, absence of natural harbour, lack of land for agriculture, and a harsh climate with heavy rain and high winds at all seasons. It took an extra-ordinary breed of people, ready to live at the margins of life, to settle and eventually thrive in the world's most isolated community."
It says that Tristan da Cunha "offers the world a special social and economic organisation evolved over the years, but based on the principles set out by William Glass in 1817 when he established a settlement based on equality."