Poss. HM George I's 12-Great Grandfather. Poss. HRE Charles VI's 12-Great Grandfather. Poss. U.S. President [BUSH-41]'s 26-Great Grandfather. Poss. PM Churchill's 20-Great Grandfather. Poss. Lady Diana's 21-Great Grandfather. Poss. PM Cameron's 21-Great Grandfather.