Dame Sibyl Mary Hathaway ( Collings, formerly Beaumont; 13 January 1884 – 14 July 1974) was Dame of Sark from 1927 until her death in 1974. Her 47-year rule over Sark, in the Channel Islands, spanned the reigns of four monarchs: George V, Edward VIII, George VI and Elizabeth II.
The Dame was the daughter of the eccentric Seigneur of Sark, William Frederick Collings. Sibyl learned French, Sercquiais, Norman and German prior to becoming feudal lady of Sark. She married Dudley Beaumont in 1901, and they had seven children. One of her children died in infancy, and her husband died from Spanish flu in 1918, leaving her a financially troubled widow. She succeeded her father in 1927, and immediately set about reinforcing her feudal rights and promoting tourism on the island, which she affectionately called "the last bastion of feudalism". When she remarried in 1929, her second husband, Robert Hathaway, legally became her senior co-ruler, but she kept control of the government.
Dame Sibyl's tenure saw the German occupation of the Channel Islands in the Second World War, during which she refused to evacuate and convinced the islanders to stay as well. Her eldest son and heir apparent, Francis William Beaumont, was killed in 1941, while her husband was deported to an internment camp in 1943. The Dame remains best known for her indomitable conduct during the occupation. After the war, she continued her publicity campaign, strengthening the island's tourism industry.
Having been widowed again in 1954, she went on to rule alone, and was made Dame Commander of the Order of the British Empire in 1965. She was described by a British government official as a "lady of unusual personality", and is often referred to as a benevolent dictator. Dame Sibyl died at the age of 90, and was succeeded by her grandson, Michael Beaumont.
Sibyl Mary Collings was born in Guernsey in a house that once belonged to John Allaire, her privateering great-great-grandfather, whose business dealings brought the fief of Sark to his daughter, Marie Collings.