inus ▁of ▁L ily ba e um ▁and ▁Julian ▁of ▁Cos ▁and ▁two ▁pri ests ▁Bon if ace ▁and ▁Bas il ▁represented ▁the ▁western ▁church ▁at ▁the ▁council . ▁The ▁council ▁was ▁attended ▁by ▁about ▁ 5 2 0 ▁b ish ops ▁or ▁their ▁represent atives ▁and ▁was ▁the ▁largest ▁and ▁best - document ed ▁of ▁the ▁first ▁seven ▁ec umen ical ▁coun c ils . ▁All ▁the ▁sessions ▁were ▁held ▁in ▁the ▁church ▁of ▁St . ▁Eu ph emia , ▁Mart yr , ▁outside ▁the ▁city ▁and ▁directly ▁opposite ▁Constantin ople . ▁As ▁to ▁the ▁number ▁of ▁sessions ▁held ▁by ▁the ▁Council ▁of ▁Chal ced on ▁there ▁is ▁a ▁great ▁dis cre p ancy ▁in ▁the ▁various ▁texts ▁of ▁the ▁Act s , ▁also ▁in ▁the ▁ancient ▁histor ians ▁of ▁the ▁council . ▁Either ▁the ▁respective ▁manuscript s ▁must ▁have ▁been ▁incomplete ; ▁or ▁the ▁histor ians ▁passed ▁over ▁in ▁silence ▁several ▁sessions ▁held ▁for ▁secondary ▁purposes . ▁According ▁to ▁the ▁de acon ▁R ust icus , ▁there ▁were ▁in ▁all ▁six teen ▁sessions ; ▁this ▁division ▁is ▁commonly ▁accepted ▁by ▁sch ol ars , ▁including ▁Karl ▁Josef ▁von ▁He fe le , ▁an ▁historian ▁of ▁the ▁coun c ils . ▁If ▁all ▁the ▁separate ▁meet ings ▁were ▁counted , ▁there ▁would ▁be ▁twenty - one ▁sessions ; ▁several ▁of ▁these ▁meet ings , ▁however , ▁are ▁considered ▁as ▁supp lement ary ▁to ▁preceding ▁sessions . ▁ ▁Pas chas inus ▁refused ▁to ▁give ▁Dios cor us ▁( who ▁had ▁ex communic ated