The Assyrian Church of the East

The historical roots of the Assyrian Church of the East lie beyond the Roman Empire. Therefore, representatives of this church were not involved in the first major councils of early Christianity. The Assyrian Church later recognized the decisions of the first two ecumenical councils (Nicaea 325 and Constantinople 381) but refused to recognize the decisions of the Council of Ephesus (431). Many followers of the Patriarch Nestorius, who was condemned as a heretic by the Council of Ephesus, found refuge in the Sassanid territory to the East of the empire's borders, which roughly encompassed modern-day Iraq and Iran and was home to the Assyrian Church of the East. This led to the faithful of this church being referred to as "Nestorians" for a long time, which recent research has shown to be a misconception. In the presentation of denominations, the Assyrian Church of the East is now referred to as "pre-Ephesian Orthodoxy" due to the aforementioned rejection of the decisions of the Council of Ephesus.