In200,YuanShaoamassedmorethan100,000troopsandmarchedsouthwardsonXuchanginthenameofrescuingtheemperor.CaoCaogathered20,000meninGuandu,astrategicpointontheshoreoftheYellowRiver.Thetwoarmiescometoastandstillasneithersidewasabletomakemuchprogress.CaoCao'slackofmendidnotallowhimtomakesignificantattacks,andtheprideofYuanShaoforcedhimtotargetCaoCao'sforcehead-on.DespitehisoverwhelmingadvantageintermsofmanpowerYuanShaowasunabletomakefulluseofhisresourcesbecauseofhisindecisiveleadershipandCaoCao'slocation.

　　BesidesthemiddlebattlegroundofGuandu,twolinesofbattlewerepresent.TheeasternlinewithYuanTanofYuanShao'sarmyversusZangBaofCaoCao'sarmywasaone-sidedbattleinfavorofCaoCao,asYuanTan'sownquestionableleadershipwasnomatchforXangBa'slocalknowledgeofthelandscapeandhit-and-runtactics.Tothewesternside,YuanShao'scousin,GaoGan,performedmuchbetteragainstCaoCao'sarmyandforcedseveralreinforcementsfromCaoCao'smaincamptomaintainthewesternbattle.LiuBei,whowasatthetimeaguestinYuanShao'sarmy,alsosuggestedtoinduceuprisinginthebackofCaoCao'slandsasthereweremanyconnectionstotheYuanfamilyandtheirsubordinates.Thetacticwassuccessfulatfirst,butquicklycounteredbyManChong'sdiplomaticskill.ManChonghadbeenplacedasanofficialthereforthisspecificreason,asCaoCaohadforeseenthesituationpriortothebattle.

　　Finally,withthehelpofadefectorfromYuanShao'sarmy,XuYou,whoinformedCaoCaoofthelocationofYuanShao'sarmysupply,CaoCaobrokethestandstillandsentaspecialtaskforcetoburnallthesuppliesofYuanShao'sarmyandwonadecisiveandseeminglyimpossiblevictory.YuanShaofellillanddiedshortlyafterreturningfromthedefeat,leavinghislegacytotwoofhissons–theeldestson,YuanTanandtheyoungestson,YuanShang.Ashehaddesignatedtheyoungestson,YuanShang,ashissuccessor,ratherthantheeldestastraditiondictated,thetwobrothersconsistentlyfeudedagainsteachother,astheyfoughtCaoCao.Becauseoftheirinternaldivisions,CaoCaowaseasilyabletodefeatthembyusingtheirdifferencestohisadvantage.HenceforthCaoCaoassumedeffectiveruleoverallofnorthernChina.HesentarmiesfurtheroutandextendedhiscontrolpasttheGreatWallintonorthernKorea,andsouthwardtotheHanRiver.

　　However,CaoCao'sattempttoextendhisdominationsouthoftheYangtzeRiverwasunsuccessful.HereceivedaninitialgreatsuccesswhenLiuBiao,rulerofJingZhou,died,andhissuccessor,LiuZongsurrenderedtoCaoCaowithoutresistance.Delightedbythisturn-out(CaoCao,adevotedfollowerofSunTzu'sArtofWar,alsoconsidered"defeatingyourenemywithoutbattle"tobethehighestformofachievementofwar)hepressedonandhopedthesamewouldhappendespitetheobjectionsbyhismilitaryadvisors.HisforceswerethendefeatedbythefirstcoalitionofhisarchrivalsLiuBeiandSunQuan(wholaterfoundedthekingdomsofShuandWurespectively)attheRedCliffsin208.