The dominant view in the Eastern Orthodox Church , that all Western Christians who accepted Filioque interpolation and unorthodox Pneumatology ceased to be Catholics , was held and promoted by famous Eastern Orthodox canonist Theodore Balsamon who was patriarch of Antioch . He wrote in 1190 : On the other side of the widening rift , Eastern Orthodox were considered by western theologians to be '' Schismatics '' . Relations between East and West were further estranged by the tragic events of the Massacre of the Latins in 1182 and Sack of Constantinople in 1204 . Those bloody events were followed by several failed attempts to reach reconciliation ( see : Second Council of Lyon , Council of Florence , Union of Brest , Union of Uzhhorod ) . During the late medieval and early modern period , terminology became much more complicated , resulting in the creation of parallel and confronting terminological systems that exist today in all of their complexity
Massacre of the Latins
Massacre of the Latins
Catholic (term)