Poss. HM George I's 23-Great Grandmother. Poss. HRE Ferdinand I's 20-Great Grandmother. Poss. HRE Charles VI's 23-Great Grandmother. Poss. U.S. President [John ADAMS]'s 26-Great Grandmother. Poss. Wm. von Bismarck's 28-Great Grandmother. Poss. Agnes Harris's 23-Great Grandmother.