The title of Marquess of Milford Haven was created in 1917 for Prince Louis of Battenberg, the former First Sea Lord, and a relation to the British Royal family, who became Louis Mountbatten, 1st Marquess of Milford Haven. His younger son was the famous Lord Mountbatten who served as the last Viceroy of India.
The Marquess holds the subsidiary titles of Earl of Medina (1917) and Viscount Alderney (1917).