HRH Charles's 16-Great Uncle. PM Cameron's 18-Great Uncle. HRH Albert II's 18-Great Uncle. Louis XVII's 11-Great Uncle. HM Juan Carlos' 16-Great Uncle. Philippe of Belgium's 16-Great Uncle. HM Manuel II's 15-Great Uncle. HM Beatrix's 15-Great Uncle. HM Carl XVI Gustaf's 15-Great Uncle. HM Harald V's 15-Great Uncle. Ksr Wilhelm II's 14-Great Uncle. HM Umberto II's 15-Great Uncle. `Red Baron' Richthofen's 14-Great Uncle.