HRH Charles's 16-Great Grandfather. Poss. Lady Diana's 18-Great Grandfather. HM Juan Carlos' 17-Great Grandfather. Philippe of Belgium's 17-Great Grandfather. HM Manuel II's 16-Great Grandfather. Grand Duke Henri's 17-Great Grandfather. HM Margrethe II's 16-Great Grandfather. HM Beatrix's 14-Great Grandfather. HM Constantine II's 16-Great Grandfather. HM Carl XVI Gustaf's 16-Great Grandfather. HM Harald V's 16-Great Grandfather. Ksr Wilhelm II's 14-Great Grandfather. HM Umberto II's 16-Great Grandfather. Otto von Bismarck's 12-Great Grandfather. `Red Baron' Richthofen's 15-Great Grandfather. HRH Catharina-Amalia's 16-Great Grandfather.