The Armenian Orthodox Church, also called the Armenian Apostolic Church, is one of the original Oriental Orthodox churches, having separated from the then-still-united Catholic/Orthodox church in 506, after the Council of Chalcedon. The Armenian church has been labeled monophysite because they rejected the decisions of this council, which condemned monophysitism. The Coptic Orthodox Church also separated after the Coucil of Chalcedon. The head of the Armenian Orthodox Church is the Catholicos of Armenia (the plural is Catholicoi). The Armenian Apostolic Church should not be confused, however, with the Armenian Catholic Church, which is an Eastern Rite church under the authority of the Pope in Rome.
Today there are large Armenian Orthodox congreations in many middle-eastern countries outwith Armenia. Of particular importance is the Armenian Apostolic Church of Iran (See also Christians in Iran], where Armenians are the largest Christian ethnic minority.
Other large Armenian Orthdox congregations are in the USA and in many Western European countries.