Poss. HM George I's 10-Great Grandmother. Poss. HRE Charles VI's 11-Great Grandmother. Poss. U.S. President [BUSH-41]'s 23-Great Grandmother. HRH Charles's 19-Great Grandmother. PM Churchill's 19-Great Grandmother. Lady Diana's 21-Great Grandmother. PM Cameron's 21-Great Grandmother. HRH Albert II's 19-Great Grandmother. Louis XVII's 14-Great Grandmother.