Captain George Louis Victor Henry Serge Mountbatten, 2nd Marquess of Milford Haven (6 November 1892[1] – 8 April 1938), born Prince George of Battenberg, styled Earl of Medina between 1917 and 1921, was a Royal Navy officer and the elder son of Louis Mountbatten, 1st Marquess of Milford Haven (Prince Louis of Battenberg), and Princess Victoria of Hesse and by Rhine.

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."

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[4] and to commander on 31 December 1926.

[7] An accomplished mathematician, the Marquess "could work out complicated gunnery problems in his head" and "read books on calculus casually on trains".

[9] Prince George of Battenberg, as he then was known, married Countess Nadejda Mikhailovna de Torby (daughter of Russian Grand Duke Michael Mikhailovich Romanov and his morganatic wife, Countess Sophie von Merenberg) on 15 November 1916 at the Russian Embassy, Welbeck Street, London.