Southern Thule is a collection of the three southernmost islands in the South Sandwich Islands: Bellingshausen, Cook, and Thule (Morrell). Southern Thule is British territory, though claimed by Argentina. The island group is barren, windswept, bitterly cold, and uninhabited, of no real strategic or economic value. The Admiralty's Antarctic Pilot says that Southern Thule is part of an old sunken volcano, and is covered with ash and penguin guano. There are seals, petrels, and a bank of kelp just offshore, especially around a small inlet on Morrell called Ferguson Bay.
The island group was first sighted by in 1775 by the expedition of James Cook, who named it Southern Thule because it seemed to lie at very much the extreme end of the world (see Ultima Thule). It was further explored in 1820 by Bellingshausen who established that it consisted of three separate islands.
In November 1976 a party from the Argentine Air Force landed on Thule, and, without informing the British Government, constructed a small military base complete with barracks and a small concrete helicopter landing pad. They set up a weather station, a radio station, and a flagpole from which the Argentine flag flew. All this was done at the direction of the Argentine Government in order to back up their territorial claim to the South Sandwich Islands. The base was named Corbeta Uruguay.
It was not until December 1976 that the British discovered what had happened. The Argentine action became the subject of a number of official British protests, the first of them on 19 January 1977. Arrangements to legitimise the station were discussed in 1978 but failed. More than a year went by before word of the occupation of Southern Thule leaked out to the public. The then Prime Minister, James Callaghan, ruled out sending in the Royal Marines to end the occupation, preferring diplomacy. This unwillingness to project force, plus the British Government's intention to cut back the British military presence in the Antarctic for financial reasons, led the Argentine Government to believe that they could successfully occupy and annex the Falkland Islands and South Georgia, which they attempted in April 1982, sparking the Falklands War.
The Argentine presence remained on Southern Thule until six days after the Falklands War had ended. On June 20, 1982, several British warships landed Royal Marines and the Argentine garrison, outnumbered and outgunned, surrendered and handed over their weapons.
After the surrender, Southern Thule was left deserted, but six months later, a passing British warship noticed that the Union Flag had been taken down from the flagpole at the deserted base and the flag of Argentina run up in its place. When word of this reached London, the military was ordered to destroy all buildings on Southern Thule, leaving Corbeta Uruguay unfit for prolonged habitation. By Christmas 1982, the barrack block, mess room, and meteorological station were reduced to a pile of concrete rubble, leaving only a small hut stocked with emergency supplies and the flagpole, which was last seen flying the Union Flag.