Operation Tabarin was a World War II military undertaking by the Admiralty and the Colonial Office in 1943 to establish a permanent British presence in the Antarctic. The bases built were the first ever to be constructed in Antarctica.

There have been several reasons cited for Tabarin. Prior to the start of the war, German aircraft had dropped markers with swastikas across Queen Maud Land in an attempt to create a territorial claim (see New Swabia). In 1943, British personnel from HMS Carnarvon Castle removed Argentine flags from Deception Island. There were also concerns within the Foreign Office about the direction of United States post-war activity in the region. So the chief reason was to establish solid British claims to various uninhabited islands and parts of Antarctica, reinforced by Argentine sympathies toward Germany.
A suitable cover story was the need to deny use of the area to the enemy. The Kriegs marine was known to use remote islands as rendezvous points and as shelters for commerce raiders, U-boats, and supply ships. Also, in 1941, there existed a fear that Japan might attempt to seize the Falkland Islands, either as a base or to hand them over to Argentina, thus gaining political advantage for the Axis and denying their use to Britain. Deception Island, in the British South Shetland Islands, possessed a sheltered anchorage with an old Norwegian whaling station. In 1941, the British (aboard HMS Queen of Bermuda) had taken the precaution of destroying coal dumps and oil tanks there, to prevent their possible use by the Germans.
Led by Lieutenant James Marr, the 14-strong team left the Falkland Islands in two ships, HMS William Scoresby (a minesweeping trawler) and ss Fitzory on Saturday

29 January 1944.
Bases were established during February near the abandoned Norwegian whaling station on Deception Island, where the Union Flag was hoisted in place of Argentine flags, and at Port Lockroy (on 11 February) on the coast of Graham Land. A further base was founded at Hope Bay on 13 February, 1945, after a failed attempt to unload stores on 7 February, 1944.

HMS William Scoresby, after World War 2, became RFA William Scoresby