HRH Charles's 14-Great Grandfather. Lady Diana's 14-Great Grandfather. HM Juan Carlos' 14-Great Uncle. Philippe of Belgium's 14-Great Grandfather. Grand Duke Henri's 14-Great Grandfather. HM Margrethe II's 14-Great Grandfather. HM Beatrix's 14-Great Grandfather. HM Constantine II's 14-Great Grandfather. HM Harald V's 14-Great Grandfather.