are an archipelago in the South Atlantic Ocean, located over 250 nautical miles (460 km; 290 mi) east of the coast of mainland South America. The archipelago comprises East Falkland, West Falkland, and 776 lesser islands. Stanley, the capital and only city, is on East Falkland. The islands are a self-governing British Overseas Territory, with the United Kingdom responsible for its defence and foreign affairs. Controversy exists over the Falklands' original discovery and subsequent colonisation by Europeans. At various times there have been French, British, Spanish, and Argentine settlements. Britain re-established its rule in 1833, yet the islands continue to be claimed by Argentina. In 1982, following Argentina's invasion of the islands, the two-month-long undeclared Falklands War between both countries resulted in the withdrawal of Argentine forces. Despite its defeat, Argentina still pursues its claim; however, UK policy supports the islanders' self-determination to remain British citizens. The population, estimated at 3,140, primarily consists of Falkland Islanders, the majority of British descent. Other ethnicities include French, Gibraltarian, and Scandinavian. Immigration from the United Kingdom, Saint Helena, and Chile has reversed a former population decline. The predominant and official language is English. Under the British Nationality Act of 1983, Falkland Islanders are British citizens. Both major islands have mountain ranges, both reaching to around 700 metres (2,300 ft). The islands are home to large bird populations, although many no longer breed on the main islands due to introduced species. Major economic activities include fishing, tourism, and sheep farming (used for high-quality wool exports). Oil exploration, licensed by the Falkland Islands Government, remains controversial as a result of maritime disputes with Argentina.