The validity of the Western legates ' act is doubtful , since Pope Leo had died and Cerularius ' excommunication applied only to the legates personally . Still , the Church split along doctrinal , theological , linguistic , political , and geographical lines , and the fundamental breach has never been healed , with each side sometimes accusing the other of having fallen into heresy and of having initiated the division . The Latin led Crusades , the Massacre of the Latins in 1182 , the West 's retaliation in the Sacking of Thessalonica in 1185 , the capture and pillaging of Constantinople by the Fourth Crusade in 1204 , and the imposition of Latin patriarchs made reconciliation more difficult . Establishing Latin hierarchies in the Crusader states meant that there were two rival claimants to each of the patriarchal sees of Antioch , Constantinople , and Jerusalem , making the existence of schism clear . Several attempts at reconciliation did not bear fruit . In 1965 , Pope Paul VI and the Ecumenical Patriarch of Constantinople Athenagoras I nullified the anathemas of 1054 , although this nullification of measures taken against a few individuals was essentially a goodwill gesture and did not constitute any sort of reunion . Contacts between the two sides continue : every year a delegation from each joins in the other 's celebration of its patronal feast , Saints Peter and Paul ( 29 June ) for Rome and Saint Andrew ( 30 November ) for Constantinople , and there have been a number of visits by the head of each to the other . The efforts of the Ecumenical Patriarchs towards reconciliation with the Catholic Church have often been the target of sharp criticism from some fellow Orthodox
Massacre of the Latins
Massacre of the Latins
East–West Schism