HM George I's 6-Great Grandfather. HRE Charles VI's 7-Great Grandfather. Lady Diana's 15-Great Uncle. PM Cameron's 15-Great Grandfather. HRH Albert II's 15-Great Grandfather. HM Margrethe II's 13-Great Grandfather. Wm. von Bismarck's 11-Great Uncle. Boris Johnson's 15-Great Grandfather. `Red Baron' Richthofen's 11-Great Grandfather.