821 (DCCCXXI) ebile ngwaga wa go thoma ka Labohlano, ngwaga wa bobedi ngwagengsome wa 820s, ngwaga wa bomasomepedi tee ngwagengkgolo wa Ngwagakgolo 9, le ngwaga wa bomakgolo seswai masomepedi tee ngwagengkete wa Ngwagakete 1.