Poss. HM George I's 15-Great Grandfather. Poss. HRE Charles VI's 17-Great Grandfather. Poss. U.S. President [WASHINGTON]'s 20-Great Grandfather. Poss. PM Churchill's 23-Great Grandfather. Poss. Lady Diana's 23-Great Grandfather. Poss. PM Cameron's 25-Great Grandfather. Poss. Jamie's 27-Great Grandfather.