HRH Charles's 22-Great Uncle. Lady Diana's 23-Great Uncle. HM Juan Carlos' 20-Great Grandfather. Philippe of Belgium's 20-Great Grandfather. Grand Duke Henri's 19-Great Grandfather. HM Margrethe II's 20-Great Grandfather. Wm. von Bismarck's 14-Great Grandfather. `Red Baron' Richthofen's 16-Great Grandfather.