Prince Matila Costiescu Ghyka (; born Matila Costiescu; 13 September 1881 – 14 July 1965), was a Romanian naval officer, novelist, mathematician, historian, philosopher, academic and diplomat. He did not return to Romania after World War II, and was one of the most significant members of the Romanian diaspora. His first name is sometimes written as Matyla. Life Ghyka was born in Iași, the former capital of Moldavia, of the Ghica family of boyars. His mother was Maria Ghyljia and his father was Matila Costiecu, a Wallachian officer. Maria's half-brother was Grigoire Ghyka, who adopted Matila when he was a teenager so that he would acquire the title of Prince as Matila was the great-grandson of Grigore Alexandru Ghica, last reigning Prince of Moldavia before the union of the Danubian Principalities. However, much of Ghyka's inherited capital was via his grandmother's Balş family. As a boy he lived in France studying first at the Salesian Order school in Paris, then a Jesuit college in Jersey where he became interested in mathematics. In his early teens he was a cadet at the French Naval Academy in Brest, and of the last generation in the old sailing ship Borda. He became a French Navy midshipman and made a cruise in a frigate to the Caribbean. In later years he attended the École supérieure d'électricité de Paris, and finally took a doctorate in Law at the Université libre de Bruxelles. Ghyka entered the Romanian Navy as a junior officer, serving mainly on the Danube. He was also involved in taking newly constructed river gunboats from the Thames Iron Works to Romania via European waterways. During the First World War he was Romanian Navy liaison officer on the Russian cruiser Rostislav, acting as a shore bombardment director along the Black Sea coast. He had joined the diplomatic service in 1909, being stationed at the Romanian Legations in Rome, Berlin, London, Madrid, Paris, Vienna, Stockholm (as Minister Plenipotentiary) and twice again in London between 1936-1938 and between 1939 and 1940. In 1918, at the Brompton Oratory, he married Eileen O'Conor (1897-1963), daughter of the late Sir Nicholas Roderick O'Conor (d. 1908), the former British Ambassador to Istanbul and Saint Petersburg, and Minna Margaret Hope-Scott. Eileen belonged to a junior branch of the Ó Conchobhair Donn, who had anciently been Kings of Connacht. During his first diplomatic assignments in London and Paris, Prince Ghyka was introduced