HRH Charles's 10-Great Grandfather. Louis XVII's 6-Great Grandfather. HM Juan Carlos' 11-Great Grandfather. Philippe of Belgium's 11-Great Grandfather. HM Manuel II's 10-Great Grandfather. Grand Duke Henri's 11-Great Grandfather. HM Margrethe II's 10-Great Grandfather. HM Beatrix's 11-Great Grandfather. HM Constantine II's 10-Great Grandfather. HM Carl XVI Gustaf's 10-Great Grandfather. HM Harald V's 10-Great Grandfather. HM Umberto II's 11-Great Grandfather.