HM George I's 15-Great Grandfather. U.S. President [WASHINGTON]'s 15-Great Grandfather. PM Churchill's 18-Great Grandfather. Lady Diana's 20-Great Grandfather. PM Cameron's 20-Great Grandfather. Louis XVII's 19-Great Grandfather. Gen. Pierpont Hamilton's 20-Great Grandfather. Poss. `Osawatomie' Brown's 16-Great Grandfather. Jamie's 22-Great Grandfather.