David Mountbatten, 3rd Marquess of Milford Haven (12 May 1919--14 April 1970), 2nd child and only son of George, 2nd Marquess of Milford Haven, nee Prince George of Battenberg. David was a close friend of his cousin Prince Philip and, like him, served in the Royal Navy during WWII, receiving the Distinguished Service Cross in 1943. David married twice but had children only with his 2nd wife, Janet Bryce. (His older sister, Tatiana, was mentally unstable and never married nor had children.)
