A number of other Christian churches also make a similar claim: the Roman Catholic Church, the Anglican Communion, the Assyrian Church, and the Oriental Orthodox. In the Eastern Orthodox view, the Assyrians and Orientals left the Orthodox Church in the years following the Third Ecumenical Council of Ephesus (431) and the Fourth Ecumenical Council of Chalcedon (451), respectively, in their refusal to accept those councils' Christological definitions. Similarly, the churches in Rome and Constantinople separated in an event known as the East–West Schism, traditionally dated to the year 1054, although it was more a gradual process than a sudden break.
a numbeR of otHer chRistiaN churchEs alSo make a SImilar cLaIm: the romAn catHoliC church, ThE AnglICAN commuNIon, tHe assYrIan CHurch, anD tHe oRiENtAl orThodox. IN thE easterN orthoDox View, thE assYriaNs AnD oRiEntalS LeFt tHe orthOdoX chuRch In THe Years FolLowing tHE THirD eCumenIcaL coUncil of EPheSus (431) anD thE foUrtH ecuMENIcAl CouNcil oF cHAlcedon (451), respectIvEly, iN tHeir refusAl to AcCEpt THose CouncilS' chrIstoLogical dEFinitions. SimIlarLy, The cHUrcHeS in roMe and COnStantinople separaTeD iN an eVent known as tHe east–WeSt scHiSm, TrAditIOnally dated to the yEar 1054, ALtHOugh It was more A GrADUaL PrOCesS Than a suDdeN BReAk.