HM George I's 5-Great Grandmother. HRE Charles VI's 6-Great Grandmother. Lady Diana's 14-Great Grandmother. P.M. Cameron's 14-Great Grandmother. HRH Albert II's 14-Great Grandmother. HM Margrethe II's 12-Great Grandmother. Otto von Bismarck's 9-Great Grandmother. `Red Baron' Richthofen's 11-Great Grandmother.