HRH Charles's 16-Great Uncle. HM Juan Carlos' 13-Great Grandfather. Philippe of Belgium's 13-Great Grandfather. HM Manuel II's 14-Great Uncle. Grand Duke Henri's 13-Great Grandfather. HM Margrethe II's 12-Great Grandfather. HM Beatrix's 12-Great Grandfather. HM Constantine II's 13-Great Grandfather. HM Carl XVI Gustaf's 13-Great Grandfather. HM Harald V's 12-Great Grandfather. `Red Baron' Richthofen's 12-Great Grandfather.