The Coptic Orthodox Church of Alexandria is the official name for the largest Christian church in Egypt and the Middle East. The Church belongs to the Oriental Orthodox family of churches, which has been a distinct church body since the Council of Chalcedon in AD 451, when it took a different position over Christological theology from that of the Eastern Orthodox Church.
The precise differences in theology that caused the split with the Coptic Christians are still disputed, highly technical and mainly concerned with the nature of Christ. The foundational roots of the Church are based in Egypt but it has a worldwide following. According to tradition, the church was established by Saint Mark the apostle and evangelist in the middle of the 1st century (approximately AD 42). The head of the church and the See of Alexandria is the Pope of Alexandria and Patriarch of All Africa on the Holy See of Saint Mark.
As of 2012, about 10% of Egyptians belong to the Coptic Orthodox Church of Alexandria.