A healthy correspondence of Eulogius of Alexandria with Gregory the Great of Rome is evident from the fourteen books of Gregory's letters called the Registrum. After the Arab conquest of Egypt in the 7th century – which permanently separated the region from the Byzantine Empire – the Greek Chalcedonians became an isolated minority in the region, even among Christians, and the church has remained small for centuries.
A small portion of the Church of Alexandria followed Chalcedonian Christology, and this is called the Greek Orthodox Church of Alexandria, since it used Greek as its liturgical language. These Greek Chalcedonian believers were loyal to the Eastern Roman Emperor and in communion with the Patriarchs in Rome, Antioch, Constantinople, and Jerusalem.