George was born 6 November 1892 in
Darmstadt in the
Grand Duchy of Hesse, then ruled by his maternal uncle
Ernest Louis, Grand Duke of Hesse. From birth, he was a prince of the Hessian royal family, albeit of a
morganatic branch. His siblings were
Princess Alice (mother of
Prince Philip, Duke of Edinburgh, to whom he was a mentor in Philip's adolescence),
Queen Louise of Sweden and
Louis Mountbatten, 1st Earl Mountbatten of Burma (who assumed the role of Philip's mentor after George's death). George followed his father into the
Royal Navy, and after passing out from the
Royal Naval College at Dartmouth, was promoted to
sub-lieutenant on 15 January 1913. He was promoted to lieutenant on 15 February 1914, and served in the
First World War. In 1917, his father and several of his relations relinquished their German names, styles and titles in exchange for British peerages at the behest of
George V. Accordingly, Prince George dropped the style of
Serene Highness and his surname was anglicised to "Mountbatten." When his father was created
Marquess of Milford Haven in late 1917, George received the
courtesy title of
Earl of Medina, succeeding to his father's peerage after his death in September 1921. Lord Milford Haven, as George was now known, remained in the Royal Navy after the war; he was promoted to lieutenant-commander on 15 February 1922 and to commander on 31 December 1926. In 1932, he retired from active service at his own request, with effect from 9 December of that year. On 6 November 1937, shortly before his death, he was promoted to the rank of
captain on the retired list. An accomplished mathematician, the
Marquess "could work out complicated gunnery problems in his head" and "read books on
calculus casually on trains".
Queen Elizabeth II, his niece-in-law, considered him "one of the most intelligent and brilliant of people". ==Marriage and issue==