Non-Chalcedonianism

Non-Chalcedonianism is the view(s) of those churches that accepted the First Council of Ephesus of 431, but, for varying reasons, did not accept allegiance to the Council of Chalcedon following it in 451. The most substantial Non-Chalcedonian tradition is known as Oriental Orthodoxy. Within this tradition are a number of ancient Christian groups including the Coptic Orthodox, the Syriac Orthodox (sometimes referred to as "Jacobite"), the Armenian Orthodox, the Ethiopian Orthodox, the Eritrean Orthodox, and the Malankara (Indian) Orthodox.

While the Church of the East (i.e., Nestorian Christianity) also did not accept the Council of Chalcedon, in addition to that it rejected the First Council of Ephesus as well and has, according to the traditional interpretation, an opposite Christology to the Oriental Orthodox. It may thus be called "Non-Ephesine".

Within the Patriarchates of Alexandria and Antioch, the rejection of Chalcedon became a cause of schism. While the common population of Egyptian and Syrian people mostly objected to the Council, the Byzantine-Greek minority that formed the ruling class mostly accepted the Council. These two parties vied and battled for possession of the ancient sees of Alexandria and Antioch that formed, at the time, the third and fourth most prestigious sees in "Christendom", respectively. Ultimately neither group absolutely dominated either church and the end result was the existence of two distinct patriarchates of Alexandria and Antioch for almost 1500 years and continuing in the present time. What is now known as the Coptic Orthodox Church is the native Egyptian patriarchal faction of Alexandria that rejected Chalcedon, whereas the Greek Orthodox Church of Alexandria is composed of those who accepted Chalcedon. For Antioch, the Syriac Orthodox Church forms the patriarchal faction of the native Syrian-Semitic population for the church of Antioch, whereas the Greek Orthodox Church of Antioch is composed of those who accepted Chalcedon.

On the other hand, in India, and somewhat in Persia, schism occurred rather between the Oriental Orthodox and the Assyrian Church of the East. Even in Kerala today, there is a continuing presence of both the Assyrian Church of the East and the Syriac/Malankara Orthodox Church.