Chalcedonian Schism in the context of "Nestorianism"

The Greek Orthodox Patriarchate of Alexandria and all Africa (Ancient Greek: Πατριαρχεῖον Ἀλεξανδρείας καὶ πάσης Ἀφρικῆς, romanized: Patriarkheîon Alexandreías ke pásīs Afrikês, lit. 'The Patriarchate of Alexandria and all Africa'), also known as the Greek Orthodox Church of Alexandria, is an autocephalous patriarchate that is part of the Eastern Orthodox Church. Its seat is in Alexandria, and it has canonical responsibility for the entire African continent.

It is commonly called the Greek or Eastern Orthodox Patriarchate of Alexandria to distinguish it from the Coptic Orthodox Patriarchate of Alexandria. Members of the Greek Orthodox Patriarchate were once referred to as "Melkites" by non-Chalcedonian Christians because they remained in communion with the Ecumenical Patriarchate of Constantinople after the schism that followed the Council of Chalcedon in 451. Mark the Evangelist is considered the founder of the See, and the Patriarchate's emblem is the Lion of Saint Mark.

In the 5th century in Christianity, there were many developments which led to further fracturing of the State church of the Roman Empire. Emperor Theodosius II called two synods in Ephesus, one in 431 and one in 449, that addressed the teachings of Patriarch of Constantinople Nestorius and similar teachings. Nestorius had taught that Christ's divine and human nature were distinct persons, and hence Mary was the mother of Christ but not the mother of God. The Council rejected Nestorius' view causing many churches, centered on the School of Edessa, to a Nestorian break with the imperial church. Persecuted within the Roman Empire, many Nestorians fled to Persia and joined the Sassanid Church (the future Church of the East) thereby making it a center of Nestorianism. By the end of the 5th century, the global Christian population was estimated at 10-11 million. In 451 the Council of Chalcedon was held to clarify the issue further. The council ultimately stated that Christ's divine and human nature were separate but both part of a single entity, a viewpoint rejected by many churches who called themselves miaphysites. The resulting schism created a communion of churches, including the Armenian, Syrian, and Egyptian churches, that is today known as Oriental Orthodoxy. In spite of these schisms, however, the imperial church still came to represent the majority of Christians within the Roman Empire.

At the end of the 4th century the Roman Empire had effectively split into two states although its economy and the Church were still strongly tied. The two halves of the empire had always had cultural differences, in particular exemplified by the widespread use of the Greek language in the Eastern Empire and the more limited use of Greek in the West (Greek was used in the West but Latin was displacing it as the spoken vernacular. By the 5th century scholars in the West had begun to abandon Greek in favor of the use of Latin. The Church in Rome, in particular, began to encourage the use of Latin in the western provinces and published Jerome's Vulgate, the first authorized translation of the Bible in Latin.

Christianity arrived to Africa in the 1st century AD; as of 2024, it is the largest religion on the continent. Several African Christians influenced the early development of Christianity and shaped its doctrines, including Tertullian, Perpetua, Felicity, Clement of Alexandria, Origen of Alexandria, Cyprian, Athanasius and Augustine of Hippo. In the 4th century, the Aksumite empire in modern-day Ethiopia and Eritrea became one of the first regions in the world to adopt Christianity as its official religion, followed by the Nubian kingdoms of Nobatia, Makuria and Alodia and several Christian Berber kingdoms.

The Islamic conquests into North Africa brought pressure on Christians to convert to Islam due to special taxation imposed on non-Muslims and other socio-economic pressures under Muslim rule, although Christians were widely allowed to continue practicing their religion. The Eastern Orthodox Church of Alexandria and Coptic Orthodox Church of Alexandria (which separated from each other during the Chalcedonian Schism) in Egypt and the Orthodox Tewahedo Church survived Muslim invasion. Islamization of Muslim-ruled territory occurred progressively over the next few centuries, though this process is not fully understood by historians. Restrictions on church building and demolition of churches in Egypt, along with occasional persecutions such as during the reign of al-Hakim (996–1021), put additional pressure on Copts in Egypt. In the Middle Ages, the Ethiopian Empire was the only region of Africa to survive as a Christian state after the expansion of Islam. The Ethiopian church held its own distinct religious customs and a unique canon of the Bible. Therefore, the Ethiopian church community is globally unique in that it wasn't Christianised through European missionaries, but was highly independent and itself spread missionaries throughout the rest of Africa prior to the contact of European Christians with the continent.