Poss. HM George I's 20-Great Grandmother. Poss. HRE Ferdinand I's 18-Great Grandmother. Poss. HRE Charles VI's 22-Great Grandmother. Poss. U.S. President's 25-Great Grandmother. Poss. PM Churchill's 28-Great Grandmother. Poss. Otto von Bismarck's 24-Great Grandmother. Poss. `Osawatomie' Brown's 29-Great Grandmother.