Mountbatten is the family name originally adopted by a branch of the Battenberg family during World War I because of rising anti-German sentiment among the British public. On 14 July 1917, Prince Louis of Battenberg ("Prince Louis I") assumed the surname Mountbatten (having rejected an alternative translation, "Battenhill") for himself and his descendants and was created Marquess of Milford Haven. The name is an Anglicisation of the German Battenberg, a small town in Hesse. The title of count of Battenberg, later prince of Battenberg, was granted to a morganatic branch of the House of Hesse-Darmstadt in the mid 19th century.
Prince Philip of Greece and Denmark, the consort of now-Queen Elizabeth II, adopted the surname of Mountbatten from his mother's family in 1947, although he is a member of the House of Schleswig-Holstein-Sonderburg-Glücksburg by patrilineal descent.
Read more about Mountbatten: Current Holder of The Marquessate, Notable Mountbattens