HM George I's 18-Great Grandmother. HRE Ferdinand I's 16-Great Grandmother. U.S. President [WASHINGTON]'s 20-Great Grandmother. PM Churchill's 25-Great Grandmother. HM Margrethe II's 25-Great Grandmother. Wm. von Bismarck's 24-Great Grandmother. Poss. Agnes Harris's 18-Great Grandmother. Poss. `Osawatomie' Brown's 23-Great Grandmother.