The elder sister of David Bowes-Lyon married a prince who was the last Emperor of what country?
George VI George VI (Albert Frederick Arthur George; 14 December 1895 – 6 February 1952) was King of the United Kingdom and the Dominions of the British Commonwealth from 11 December 1936 until his death. He was the last Emperor of India and the first Head of the Commonwealth.
Ernest I, Duke of Saxe-Coburg and Gotha Ernest I (German: "Ernst Anton Karl Ludwig Herzog" ; 2 January 1784 – 29 January 1844) was the last sovereign duke of Saxe-Coburg-Saalfeld (as Ernest III) and, from 1826, the first sovereign duke of Saxe-Coburg and Gotha (as Ernest I). He was the father of Albert, Prince Consort of Queen Victoria and is thus a patrilineal ancestor and great-great-great-grandfather of Queen Elizabeth II. Ernest fought against Napoleon Bonaparte and through construction projects and the establishment of a court theatre left a strong imprint on his residence town, Coburg.