HRH Charles's 17-Great Uncle. Poss. Lady Diana's 16-Great Uncle. HM Juan Carlos' 16-Great Uncle. Philippe of Belgium's 16-Great Uncle. HM Manuel II's 13-Great Grandfather. Grand Duke Henri's 16-Great Uncle. HM Beatrix's 14-Great Grandfather. HM Umberto II's 13-Great Grandfather. Wm. von Bismarck's 11-Great Uncle.