The Oriental Orthodox communion comprises six churches: Armenian Apostolic, Coptic Orthodox, Syriac Orthodox, Ethiopian Orthodox, Eritrean Orthodox, Malankara Orthodox (Indian Orthodox Church).
The Oriental Orthodox Churches are heirs to some of the richest and most ancient traditions in the Christian world. Each of the six churches traces its origins to apostolic missions of the first century. Saints Thaddeus and Bartholomew are believed to have been martyred in Armenia; St. Mark is referred to as the first bishop of Alexandria; St. Philip is said to have baptized an Ethiopian pilgrim, who returned home to spread the faith in African lands south of Egypt; Antioch is mentioned in the book of Acts as the place where the term “Christian” was first used; and St. Thomas is believed to have been martyred in South India.
The Oriental Orthodox Churches were united with Rome and Byzantium in a common profession of faith until the fifth century, when the Council of Chalcedon (451) proclaimed Christ to have two distinct natures–human and divine–united in one person. While the Roman and Byzantine Churches came to accept Chalcedon as the Fourth Ecumenical Council, the Oriental Orthodox Churches acknowledge only the first three (the First Council of Nicaea, the First Council of Constantinople, and the First Council of Ephesus). Their theology, which closely follows the teaching of St. Cyril of Alexandria, holds that Christ has only one nature, at once human and divine.