HRH Charles's 18-Great Aunt. HM Juan Carlos' 17-Great Aunt. Philippe of Belgium's 17-Great Aunt. HM Manuel II's 16-Great Aunt. Grand Duke Henri's 17-Great Aunt. HM Margrethe II's 16-Great Aunt. Ksr Wilhelm II's 15-Great Aunt. `Red Baron' Richthofen's 13-Great Grandmother.