After the war, Philip was granted permission by George VI to marry Elizabeth. Before the official announcement of their engagement in July 1947, he abandoned his Greek and Danish titles and styles, became a naturalised British subject, and adopted his maternal grandparents' surname Mountbatten. He married Elizabeth on 20 November 1947. Just before the wedding, the King granted Philip the style "His Royal Highness" and created him Duke of Edinburgh, Earl of Merioneth, and Baron Greenwich. Philip left active military service when Elizabeth became queen in 1952, having reached the rank of commander, and was made a British prince in 1957. Philip had four children with Elizabeth: Charles, Prince of Wales; Anne, Princess Royal; Prince Andrew, Duke of York; and Prince Edward, Earl of Wessex. Through a British Order in Council issued in 1960, descendants of Philip and Elizabeth not bearing royal styles and titles can use the surname Mountbatten-Windsor, which has also been used by some members of the royal family who hold titles, such as Anne, Andrew and Edward.