HRH Charles's 18-Great Grandfather. HRH Albert II's 17-Great Grandfather. HM Juan Carlos' 16-Great Grandfather. Philippe of Belgium's 16-Great Grandfather. HM Manuel II's 14-Great Grandfather. Grand Duke Henri's 16-Great Grandfather. HM Beatrix's 16-Great Grandfather. HM Harald V's 16-Great Grandfather. Ksr Wilhelm II's 15-Great Grandfather. HM Umberto II's 15-Great Grandfather.