History of Orkney should continue to be observed in Orkney and Shetland. Thus the udal succession and mode of land tenure (that is, absolute freehold as distinguished from feudal tenure) lingered to some extent, and the remaining udallers held their lands and passed them on without written title. The islands cluster round the huge deep-water anchorage of Scapa Flow like a protecting hand, and in both World War I and World War II, the Royal Navy had a major base there, enabling them to challenge any attempt by German warships to emerge into the ocean through the Norwegian Sea. After the Armistice in
South Orkney Islands station house up to 45 people during the summer, and an average of 14 during winter. The British Antarctic Survey base, Signy Research Station, is located on Signy Island and was established in 1947. Initially operated year-round, since 1995/6 the Signy Research Station has been open only from November to April each year (southern hemisphere summer). Apart from personnel at the bases, there are no permanent inhabitants on the islands. The South Orkney Islands were discovered in 1821 by two sealers, the American Nathaniel Brown Palmer and the British George Powell. The Islands were originally named "Powell's Group", with the