Poss. Lady Diana's 16-Great Grandfather. HM Juan Carlos' 16-Great Grandfather. Philippe of Belgium's 16-Great Grandfather. Grand Duke Henri's 16-Great Grandfather. HM Margrethe II's 16-Great Grandfather. HM Beatrix's 15-Great Grandfather. HM Carl XVI Gustaf's 16-Great Grandfather. HM Harald V's 15-Great Grandfather. Wm. von Bismarck's 11-Great Grandfather. `Red Baron' Richthofen's 13-Great Grandfather.