HRH Charles's 13-Great Aunt. Lady Diana's 13-Great Grandmother. HM Juan Carlos' 13-Great Aunt. Philippe of Belgium's 14-Great Aunt. Grand Duke Henri's 14-Great Aunt. HM Margrethe II's 14-Great Aunt. HM Constantine II's 13-Great Grandmother. HM Carl XVI Gustaf's 13-Great Grandmother. Ksr Wilhelm II's 12-Great Aunt. HRH Catharina-Amalia's 14-Great Grandmother.