HM George I's 18-Great Grandfather. Poss. HRE Ferdinand I's 15-Great Grandfather. Poss. HRE Charles VI's 19-Great Grandfather. U.S. President [WASHINGTON]'s 20-Great Grandfather. PM Churchill's 24-Great Grandfather. Lady Diana's 25-Great Grandfather. Poss. Agnes Harris's 16-Great Grandfather. `Osawatomie' Brown's 23-Great Grandfather.