what relation was mountbatten to the queen

Lord Mountbatten was related to both Prince Philip and Queen Elizabeth II. He was a great-grandson of Queen Victoria, making him a second cousin once removed of the Queen. He was also Prince Philips uncle, as Philips mother, Princess Alice of Battenberg, was Louiss sister. Philip even lived with the Mountbattens for several years following his mothers institutionalization. Lord Mountbatten played a key role in the life of Prince Charles, who referred to him as an "honorary grandfather".