The largest Oriental Orthodox church is the Ethiopian Orthodox Tewahedo Church. The Ethiopian Orthodox Tewahedo Church, one of the few Christian churches in Sub-Saharan Africa that predates European colonization, dates back centuries and has a present membership of around 36 million people, the bulk of whom live in Ethiopia. It is a member of the World Council of Churches since its inception. Other Oriental Orthodox churches are in communion with the Ethiopian Orthodox Tewahedo Church (the Eritrean Orthodox Tewahedo Church, the Coptic Orthodox Church of Alexandria, the Malankara Orthodox Syrian Church, the Armenian Apostolic Church and the Syriac Orthodox Church).
From the first half of the fourth century until 1959, when it was granted autocephaly with its own patriarch by Saint Pope Cyril VI of Alexandria, Pope of the Coptic Orthodox Church of Alexandria, the Ethiopian Orthodox Tewahedo Church was administratively part of the Coptic Orthodox Church of Alexandria. It is one of the oldest Christian churches, and Ethiopia is just the second country in history to declare Christianity as its official religion, after Armenia (in AD 333).