- The British Antarctic Territory (BAT) is a sector of Antarctica claimed by the United Kingdom as one of its 14 British Overseas Territories, of which it is by far the largest by area. It comprises the region south of 60°S latitude and between longitudes 20°W and 80°W, forming a wedge shape that extends to the South Pole, overlapped by the Antarctic claims of Argentina (Argentine Antarctica) and Chile (Chilean Antarctic Territory). The claim to the region has been suspended since the Antarctic Treaty came into force in 1961.