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