HRH Charles's 14-Great Uncle. Poss. Lady Diana's 15-Great Grandfather. HM Juan Carlos' 15-Great Grandfather. Philippe of Belgium's 15-Great Grandfather. Grand Duke Henri's 15-Great Grandfather. HM Margrethe II's 15-Great Grandfather. HM Beatrix's 14-Great Grandfather. HM Carl XVI Gustaf's 15-Great Grandfather. HM Harald V's 14-Great Grandfather. Ksr Wilhelm II's 12-Great Uncle. Wm. von Bismarck's 10-Great Grandfather. `Red Baron' Richthofen's 12-Great Grandfather.