TheOriental Orthodox Churches areEastern Christian churches adhering toMiaphysiteChristology,^[1][2] with approximately 50 million members worldwide.^[3][4] The Oriental Orthodox Churches adhere to theNicene Christian tradition. Oriental Orthodoxy is one of the oldest branches inChristianity.^[5]

Oriental Orthodox Churches
Clockwise from top: Etchmiadzin Armenian Apostolic Cathedral, Saint Mark's Coptic Orthodox Cathedral, Enda Mariam Eritrean Orthodox Cathedral, Holy Trinity Ethiopian Orthodox Cathedral, Malankara Orthodox Syrian Catholicate Palace, Saint George Syriac Orthodox Cathedral.
Classification	Non-Chalcedonian
Orientation	Eastern Christianity
Theology	Oriental Orthodox theology
Polity	Episcopal
Structure	Communion
Autocephalous churches	Syriac Orthodox Church Coptic Orthodox Church Armenian Apostolic Church Ethiopian Orthodox Tewahedo Church Eritrean Orthodox Tewahedo Church Malankara Orthodox Church
Language	Coptic,Classical Syriac,Ge'ez,Armenian,Malayalam,Koine Greek, local languages
Liturgy	Alexandrian,West Syriac andArmenian
Founder	Jesus Christ, according tosacred tradition
Separated from	Roman state Church
Members	50 million
Other name(s)	Oriental Orthodoxy,Miaphysite churches,Oriental Orthodox Communion

As some of the oldest religious institutions in the world, the Oriental Orthodox Churches have played a prominent role in the history and culture of countries and regions such asArmenia,Egypt,Eritrea,Ethiopia,Sudan, theLevant,Iraq and theMalabar region of southernIndia. Asautocephalous churches, theirbishops are equal by virtue ofepiscopal ordination. Their doctrines recognize the validity of only the first threeecumenical councils.^[6][1]

The Oriental Orthodox communion is composed of six autocephalous national churches: theCoptic Orthodox Church of Alexandria; theSyriac Orthodox Church of Antioch and its constituent autonomousMalankara Jacobite Syrian Church; theMalankara Orthodox Syrian Church; theArmenian Apostolic Church comprising the autocephalousCatholicosate of Etchmiadzin in Armenia and theCatholicosate of Cilicia in theLevant and of diaspora; theEthiopian Orthodox Tewahedo Church, and theEritrean Orthodox Tewahedo Church.^[7][5] TheMalabar Independent Syrian Church—based in India—and theBritish Orthodox Church in theUK are independent Oriental Orthodox churches, having formerly been part of one of the mainstream Oriental Orthodox churches.^[8]

Oriental Orthodox Christians consider themselves to be theone, holy, catholic, and apostolic Church founded byJesus Christ in hisGreat Commission, and its bishops as thesuccessors of Christ'sapostles. Three rites are practiced by the churches: the western-influencedArmenian Rite, theWest Syriac Rite of the Syriac Church and the Malankara Syrian Church of India, and theAlexandrian Rite of theCopts,Ethiopians andEritreans.

Oriental Orthodox Churches sharedcommunion with theimperial Roman church before theCouncil of Chalcedon in 451 AD, and with theChurch of the East until theSynod of Beth Lapat in AD 484,^[9] separating primarily overdifferences in Christology.

The majority of Oriental Orthodox Christians live inEgypt,Ethiopia,Eritrea,India,Syria,Turkey andArmenia, with smallerSyriac communities in Western Asia decreasing due topersecution.^{[10][11][12][13]} There are also many in other parts of the world, formed throughdiaspora,conversions, and missionary activity.

The name "Oriental Orthodox Churches" was formally adopted at theConference of Addis Ababa in 1965. At the time there were five participating churches, the Eritrean Church not yet being autocephalous.^[14]

Other names by which the churches have been known includeOld Oriental,Ancient Oriental,Lesser Eastern,Anti-Chalcedonian,Non-Chalcedonian,Pre-Chalcedonian,Miaphysite orMonophysite.^[15][14] The Catholic Church has referred to these churches as "the Ancient Churches of the East".^[16]

Today, Oriental Orthodox Churches are infull communion with each other, but not with the Eastern Orthodox Church or any other churches. Like Catholics or Eastern Orthodox, the Oriental Orthodox Churches includes several self-governing churches. Slow dialogue towards restoring communion between the Eastern and Oriental Orthodox groups^[17] was renewed in the mid-20th century,^[18] and dialogue is also underway between Oriental Orthodoxy and the Catholic Church and others.^[19] In 2017, the mutual recognition ofbaptism was restored between the Coptic Orthodox Church of Alexandria and the Catholic Church.^[20] Also baptism is mutually recognized between the Armenian Apostolic Church and the Catholic Church.^[21][22]

The Oriental Orthodox Churches are generally considered to be moreconservative with regard to social issues. All Oriental Orthodox Churches are members of theWorld Council of Churches.^[23]

To the hierarchs who would lead the Oriental Orthodox, the description of Christ as "one person in two natures" was tantamount to accepting Nestorianism, which expressed itself in a terminology incompatible with their understanding of Christology. Nestorianism was understood as seeing Christ in two separate natures, human and divine, each with different actions and experiences; in contrastCyril of Alexandria advocated the formula "One Nature of God the Incarnate Logos"^[24] (or as others translate, "One Incarnate Nature of the Word"^[25]).

The Oriental Orthodox Churches were therefore often called "monophysite", although they reject this label, as it is associated withEutychian monophysitism; they prefer the term "miaphysite".^[26][27]

In the years following Chalcedon the patriarchs of Constantinople intermittently remained in communion with the non-Chalcedonianpatriarchs of Alexandria andAntioch (seeHenotikon), while Rome remained out of communion with the latter and in unstable communion with Constantinople. It was not until 518 that the new Byzantine Emperor,Justin I (who accepted Chalcedon), demanded that the church in the Roman Empire accept the council's decisions.^[28]

Ecumenical dialogue increased in the 20th century, and from several meetings between the authorities of theHoly See and the Oriental Orthodox, reconciling declarations emerged in the common statement of Syriac Patriarch MarIgnatius Zakka I Iwas and the RomanPope John Paul II in 1984:

The confusions and schisms that occurred between their Churches in the later centuries, they realize today, in no way affect or touch the substance of their faith, since these arose only because of differences in terminology and culture and in the various formulae adopted by different theological schools to express the same matter. Accordingly, we find today no real basis for the sad divisions and schisms that subsequently arose between us concerning the doctrine of Incarnation. In words and life we confess the true doctrine concerning Christ our Lord, notwithstanding the differences in interpretation of such a doctrine which arose at the time of the Council of Chalcedon.^[29]

However, despite the progress made in ecumenical dialogue, many Oriental Orthodox authorities likePope Shenouda III remained skeptical about the Chalcedonian churches, continuing to view their Christology asNestorian.^[24]

The Oriental Orthodox Churches are acommunion of sixautocephalous (that is, administratively completely independent) regional churches.^[15]

Below is a list of the six autocephalous Oriental Orthodox churches forming the main body of Oriental Orthodox Christianity. Based on the definitions, the list is in the alphabetical order, with some of their constituent autonomous churches and exarchates listed as well.

• Alexandrian Rite
  • Coptic Orthodox Church of Alexandria
    • French Coptic Orthodox Church
  • Ethiopian Orthodox Tewahedo Church
  • Eritrean Orthodox Tewahedo Church
• Syro-Antiochene Rite
  • Syriac Orthodox Church of Antioch
    • Jacobite Syrian Christian Church
  • Malankara Orthodox Syrian Church
• Armenian Rite, represented by theArmenian Apostolic Church
  • Mother See of Holy Etchmiadzin
    • Armenian Patriarchate of Constantinople
    • Armenian Patriarchate of Jerusalem
  • Holy See of Cilicia^[30]

There are a number of churches considered non-canonical, but whose members and clergy may or may not be in communion with the greater Oriental Orthodox communion. Examples include theMalabar Independent Syrian Church, theCeltic Orthodox Church, theOrthodox Church of the Gauls, theBritish Orthodox Church, and theTigrayan Orthodox Tewahedo Church. These organizations have passed in and out of official recognition, but members rarely face excommunication when recognition is ended. The primates of these churches are typically referred to asepiscopi vagantes orvagantes in short.

According to theEncyclopedia of Religion, Oriental Orthodoxy is the Christian tradition "most important in terms of the number of faithful living in the Middle East", which, along with otherEastern Christian communions, represent anautochthonous Christian presence whose origins date further back than the birth and spread ofIslam in the Middle East.^[31]

As of 2011^[update], it was the dominant religion inArmenia (94%) and ethnicallyArmenian unrecognizedNagorno-Karabakh Republic (95%).^[32][33] However, almost the entire Armenian population of Nagorno-Karabakhfled in 2023 after anAzerbaijani offensive retook it.^[34]

Oriental Orthodoxy is a prevailing religion inEthiopia (43.1%), while Protestants account for 19.4% and Islam – 34.1%.^[35] It is most widespread in two regions inEthiopia:Amhara (82%) andTigray (96%), as well as the capital city ofAddis Ababa (75%). It is also one of two major religions inEritrea (40%).^[36]

It is a minority inEgypt (<20%),^[37]Syria (2–3% out of the 10% of total Christians),Lebanon (10% of the 40% of Christians in Lebanon or 200,000 Armenians and members of the Church of the East) andKerala,India (7% out of the 20% of total Christians in Kerala).^[38] In terms of total number of members, the Ethiopian Church is the largest of all Oriental Orthodox churches, and is second among all Orthodox churches among Eastern and Oriental Churches (exceeded in number only by theRussian Orthodox Church).

Also of particular importance are the Armenian Patriarchate of Constantinople in Turkey and theArmenian Apostolic Church of Iran. These Oriental Orthodox churches represent the largest Christian minority in both of these predominantly Muslim countries,Turkey andIran.^[39][40]

The Oriental Orthodox Churches are distinguished by their recognition of only the first three ecumenical councils during the period of thestate church of the Roman Empire: theFirst Council of Nicaea in 325, theFirst Council of Constantinople in 381 and theCouncil of Ephesus in 431.

Oriental Orthodoxy shares much theology and manyecclesiastical traditions with theEastern Orthodox Church; these include a similardoctrine of salvation and a tradition of collegiality between bishops, as well as reverence of theTheotokos and use of theNicene Creed.^[41][42]

The primary theological difference between the two communions is the differing Christology. Oriental Orthodoxy rejects theChalcedonian Definition, and instead adopts themiaphysite formula,^[26][27] believing that the human anddivine natures of Christ are united in one Incarnate Nature. Historically, the early prelates of the Oriental Orthodox Churches thought that the Chalcedonian Definition implied a possible repudiation of theTrinity or a concession toNestorianism.

The break in communion between the imperial Roman and Oriental Orthodox Churches did not occur suddenly, but rather gradually over two to three centuries following the Council of Chalcedon.^[43] Eventually the two communions developed separate institutions, and the Oriental Orthodox did not participate in any of the later ecumenical councils.

The Oriental Orthodox Churches maintain ancientapostolic succession and thehistoric episcopacy.^[44] The various churches are governed byholy synods, with aprimus inter pares bishop serving asprimate. The primates hold titles such aspatriarch,catholicos, andpope. TheAlexandrian Patriarchate, theAntiochian Patriarchate along withPatriarchate of Rome, was one of the most prominent sees ofthe early Christian Church.

Oriental Orthodoxy does not have a magisterial leader like theCatholic Church, nor does the communion have a leader who can convene ecumenical synods like the Eastern Orthodox Church. Meanwhile its ecumenical dialogues and internal church relations are led by the Standing Conference of Oriental Orthodox Churches, which acts as the permanent representative council of its member churches.

The schism between Oriental Orthodoxy and the adherents of Chalcedonian Christianity was based on differences in Christology. TheFirst Council of Nicaea, in 325, declared that Jesus Christ isGod, that is to say, "consubstantial" with the Father. Later, the third ecumenical council, theCouncil of Ephesus, declared that Jesus Christ, though divine as well as human, is only one being, or person (hypostasis). Thus, the Council of Ephesus explicitly rejectedNestorianism, the Christological doctrine that Christ was two distinct persons, one divine (theLogos) and one human (Jesus), who happened to inhabit the same body.

Twenty years after Ephesus, theCouncil of Chalcedon reaffirmed the view that Jesus Christ was a single person, but at the same time declared that this one person existed "in two complete natures", one human and one divine.

At times, Chalcedonian Christians have referred to the Oriental Orthodox as beingmonophysites—that is to say, accusing them of following the teachings ofEutyches (c. 380 – c. 456), who argued that Jesus Christ was not human at all, but only divine. Monophysitism was condemned as heretical alongside Nestorianism, and to accuse a church of being monophysite is to accuse it of falling into the opposite extreme from Nestorianism. However, the Oriental Orthodox themselves reject this description as inaccurate, having officially condemned the teachings of bothNestorius and Eutyches. They define themselves as miaphysite instead,^[26][27] holding that Christ has one nature, but this nature is both human and divine.^[45]

Oriental Orthodox Christians, such as Copts, Syrians and Indians, use abreviary such as theAgpeya andShehimo, respectively, to pray thecanonical hours seven times a day while facing in theeastward direction towards Jerusalem, in anticipation of theSecond Coming of Jesus; this Christian practice has its roots inPsalm 119:164, in which the prophetDavid prays to God seven times a day.^{[46][original research?]}

Before praying, they wash their hands and face in order to be clean before and to present their best to God;shoes are removed in order to acknowledge that one is offering prayer before a holy God.^[47][48] In this Christian tradition, it is customary for women to wear aChristian headcovering when praying.^[49]

Some Oriental Orthodox Churches such as theCoptic Orthodox,Ethiopian Orthodox, andEritrean Orthodox, also place a heavier emphasis on Old Testament teachings than one might find in other Christian denominations, and its followers adhere to certain practices: followingdietary rules that are similar to JewishKashrut,^[50] require that their male members undergocircumcision,^[51] and observesritual purification.^[52][53] The Oriental Orthodox Churches also maintain differing compilations of the biblical canon including thePeshitta,Coptic andOrthodox Tewahedo canons, and theArmenian canon.

TheAssyrian Church of the East is sometimes incorrectly described as an Oriental Orthodox church,^[54][55][56] though its origins lie in disputes that predated the Council of Chalcedon and it follows a differentChristology from Oriental Orthodoxy. The historicalChurch of the East was the church ofGreater Iran and declared itself separate from thestate church of the Roman Empire in 424–27, years before the Ecumenical Councils of Ephesus and Chalcedon. Theologically, the Church of the East was affiliated with the doctrine ofNestorianism, and thus rejected theCouncil of Ephesus, which declared Nestorianism heretical in 431. The Christology of the Oriental Orthodox Churches in fact developed as a reaction against Nestorian Christology, which emphasizes the distinctness of the human and divine natures of Christ.

• Interparliamentary Assembly on Orthodoxy
• List of Christian denominations
• Oriental Orthodoxy in North America

• The Standing Conference of Oriental Orthodox Churches in America
• Common Declaration of Pope John Paul II and HH Mar Ignatius Zakka I Iwas (archived 19 July 2011)
• Joint Declarations Between the Syriac Orthodox and Roman Catholic Churches