HRH Charles's 19-Great Grandmother. HM Juan Carlos' 18-Great Grandmother. Philippe of Belgium's 18-Great Grandmother. HM Manuel II's 18-Great Grandmother. Grand Duke Henri's 18-Great Grandmother. HM Margrethe II's 18-Great Grandmother. HM Beatrix's 15-Great Grandmother. Wm. von Bismarck's 15-Great Grandmother.