The area was previously administered as part of the Falkland Islands Dependencies. The Antarctic Treaty of 1961 ended the possibility of normal settlement and commercial exploitation, so the lands south of 60 degrees were put under a separate administration, on March 3, 1962.
The lack of inhabitants has not discouraged the British government from issuing postage stamps for the territory. While the cynical might suppose this to be a ploy to sell stamps to collectors (nearly pure profit, since the stamps are sold at full face value, but run little risk of actually being used), scientists and tourists do use a small number of these stamps. The first issue came in 1963, an engraved set with 15 values ranging from 1/2p to one pound, featuring a portrait of Queen Elizabeth overlooking various scenes of human activity in Antarctica. Several additional issues in the 1960s were followed by a decimalization issue in 1971 produced by overprinting the 1963 stamps.
Since then, stamps have come out at regular intervals, about 10-20 per year in several sets, with a full definitive series every few years (polar explorers in 1973, plankton in 1984, fossils in 1990, research ships in 1993, etc). The design topics are related to either Antarctic research or to the native life of Antarctica.