, ▁putting ▁an ▁end ▁to ▁the ▁rem n ants ▁of ▁the ▁Latin ▁Empire ▁in ▁the ▁East , ▁and ▁he ▁asked ▁Latin ▁desp ots ▁in ▁the ▁East ▁to ▁cur b ▁their ▁amb itions . ▁On ▁June ▁ 2 9 , ▁ 1 2 7 4 , ▁Gregory ▁X ▁celebrated ▁a ▁mass ▁in ▁St ▁John ' s ▁Church , ▁where ▁both ▁sides ▁took ▁part . ▁The ▁council ▁declared ▁that ▁the ▁Roman ▁church ▁possessed ▁" the ▁supre me ▁and ▁full ▁prim acy ▁and ▁authority ▁over ▁the ▁universal ▁Catholic ▁Church ." ▁ ▁The ▁council ▁was ▁seem ingly ▁a ▁success ▁but ▁did ▁not ▁provide ▁a ▁last ing ▁solution ▁to ▁the ▁sch ism ; ▁the ▁em peror ▁was ▁anxious ▁to ▁he al ▁the ▁sch ism , ▁but ▁the ▁Eastern ▁cler gy ▁proved ▁to ▁be ▁obst inate . ▁However , ▁Michael ▁VII ' s ▁son ▁and ▁successor ▁And ron icus ▁II ▁rep udi ated ▁the ▁union . ▁ ▁Rus ' ▁Church ▁ ▁Mong ol ▁rule ▁in ▁K ie van ▁Rus ▁last ed ▁from ▁the ▁ 1 3 th ▁( G eng his ▁Khan ' s ▁army ▁entered ▁K ie van ▁Rus ▁in ▁ 1 2 2 0 s ) ▁through ▁the ▁ 1 5 th ▁century , ▁the ▁Rus ' ▁church ▁enjoyed ▁a ▁fav ored ▁position , ▁obtain ing ▁imm unity ▁from ▁tax ation ▁in ▁ 1 2 7 0 . ▁Through ▁a ▁series ▁of ▁wars ▁with ▁Muslim ▁countries ▁the ▁church ▁did ▁indeed ▁establish ▁itself ▁as ▁the ▁prote ctor ▁of ▁Orth odox y . ▁ ▁Tim eline ▁ ▁See ▁also