HM George I's 10-Great Grandmother. HRE Ferdinand I's 6-Great Grandmother. U.S. President [L.B. JOHNSON]'s 20-Great Grandmother. PM Churchill's 19-Great Grandmother. HM Margrethe II's 18-Great Grandmother. Poss. Gen. Pierpont Hamilton's 19-Great Grandmother. Wm. von Bismarck's 16-Great Grandmother. Boris Johnson's 19-Great Grandmother. `Red Baron' Richthofen's 16-Great Grandmother. Poss. Jamie's 21-Great Grandmother.