Prince Louis of Battenberg

Admiral of the Fleet Louis Alexander Mountbatten, 1st Marquess of Milford Haven, GCB, GCVO, KCMG, PC (24 May 1854 – 11 September 1921), formerly Prince Louis Alexander of Battenberg, was a British naval officer and German prince related to the British royal family."

Although born in Austria, and brought up in Italy and Germany, he enrolled in the United Kingdom's Royal Navy at the age of fourteen. Queen Victoria and her son the Prince of Wales (later Edward VII) occasionally intervened in his career: the Queen thought that there was "a belief that the Admiralty are afraid of promoting Officers who are Princes on account of the radical attacks of low papers and scurrilous ones".

However, Louis welcomed assignments that provided opportunities for him to acquire the skills of war and to demonstrate to his superiors that he was serious about his naval career. Posts on royal yachts and tours arranged by the Queen and Edward actually impeded his progress, as his promotions were perceived as undeserved royal favours.

After a naval career lasting more than forty years, in 1912 he was appointed First Sea Lord, the professional head of the British naval service. With the First World War looming, he took steps to ready the British fleet for combat, but his background as a German prince forced his retirement once the war began, when anti-German sentiment was running high. He changed his name and relinquished his German titles, at the behest of George V, in 1917.

He married a granddaughter of Queen Victoria, and was the father of Queen Louise of Sweden and Louis Mountbatten, 1st Earl Mountbatten of Burma, who also served as First Sea Lord from 1954 to 1959. He was the maternal grandfather of Prince Philip, Duke of Edinburgh, husband of Queen Elizabeth II.