On 21 July 1908 South Georgia, South Orkneys, South Shetlands, South Sandwich Islands and Graham Land were made dependencies of the colony. An extensive whaling and fishing industry existed, mainly based on Norway. The whaling industry declined in the 1950s and 1960s. Scientific bases in the area became permanent in 1943-4 with a meteorological station on South Georgia.

In 1962 all dependencies (except South Georgia and South Sandwich islands) were constituted a separate colony as British Antarctic Territory (see Antarctica).

The population of the Falklands rose from c.500 in 1856 to a peak of 2,350 in 1910 and has since fallen slightly. Consistently about half the total has lived in Stanley.

Postal History
Earliest mails were dependent upon casual ships connecting with the Brazil packet via Montevideo. The earliest recorded letter is dated 28 January 1827. From 1852 to 1880 a service between Stanley and Montevideo was maintained about every two months by contract or government schooner (except in 1854-6 and 1861-3, when ad hoc arrangements had to be made). In 1880 carriage of mail both in and out was made a statutory duty for any ship's master calling at Stanley. From 1880 to 1900 the mail was contracted to German steamships of the Kosmos Line operating a route Hamburg-Antwerp-Dartmouth (later Tilbury)-St Vincent - Montevideo - Stanley - Punta Arenas-Callao. This was superseded (1900-14) by a monthly service of the Pacific Steam Navigation Co. operating between Liverpool and Valparaiso. The opening of the Panama Canal in 1914 removed most shipping routes from the passage of Cape Horn and a regular service (via Montevideo) was not resumed until 1927. Occasional mail is known via Porto Gallegos, the nearest Argentinian port. From 1944 letters could be sent to Montevideo for onward transmission by air.

Before the 1982 war, there was a quarterly mail service by chartered ship direct to London. External airmail was carried weekly by Argentinian aircraft to Comodoro Rivadavia and thence to Buenos Aires (British mail by this route in sealed bags between Stanley and London.

Irregular internal mails were carried by local boats between East Falkland and West Falkland, where a P0 was opened in 1899 at Fox Bay. Regular internal services between Stanley, Fox Bay and New Island (P0 1909-17) operated from 1910. These were taken over by air in 1948. Internal distribution is now made by Land Rover over peat tracks or by float planes of the Government Air Service. In Stanley there is no house delivery, but collections are made from pillar boxes.

From 1861 until 31 December 1933 the office of postmaster was doubled by one government official or another. Prepayment of mail was not possible before 17 July 1861; PAID franks are known from 1868. There was no actual P0 at Stanley until 1887 When the government offices were moved in 1891 to the very edge of Stanley, the P0 went with them; central stores were then licensed to sell stamps and a letterbox erected.

In the dependencies, South Georgia has had a P0 since 20 November 1909. South Shetlands had a P0 from 1912 to 1931. Mails went via Buenos Aires (and, after 1912, also direct to Norway). The volume of mail from South Georgia was as great as that from Stanley. Not until 1924 were there any direct posts between the dependencies and Stanley.

The claims of sovereignty by Argentina came to a head in 1982 when the islands were invaded by a combined naval and military force on 2 April. A British Task Force was hastily formed and sailed to the South Atlantic. Ascension Island became an essential staging post and a Field P0 was established in May.

The Argentinians were defeated in June 1982 and a British garrison has been maintained ever since. British Field POs operate on the island and much of the mail is carried by British air transport via Ascension Island (q.v). A new airfield was constructed and opened in May 1985.