Church of the East

At a glance

The Church of the East grew outside the Roman Empire, with a catholicos-patriarch in Seleucia-Ctesiphon (later in other sees). It used East Syriac liturgy, honored Addai and Mari, and sent missionaries as far as China. The Xi’an stele of 781 records that mission.

It is not in communion with Constantinople’s Eastern Orthodox family, and it is not Oriental Orthodox. Oriental Orthodox churches rejected Chalcedon as too “two-nature.” The Church of the East was accused of the opposite error: dividing Christ after Nestorius. Modern dialogue says the old labels hid a shared confession that Jesus is truly God and truly man.

The Chaldean Catholic Church is the East Syriac church in communion with Rome. Do not treat an Assyrian parish as if it were Coptic, Greek, or Latin.

Origin and timeline

Christianity in Mesopotamia is old—traditions of Addai, Mari, and Thomas. The church organized under the Sasanian Empire, often under pressure as a minority among Zoroastrians. After Ephesus (431) condemned Nestorius, many in Persia refused that council’s authority and kept teachers in the school of Theodore of Mopsuestia.

The church flourished along trade routes: India (Saint Thomas Christians), Central Asia, and Tang China. Islam, later Mongol politics, and Timur’s campaigns reduced it. In the sixteenth century a union movement produced the Chaldean Catholic patriarchate. The remaining independent line is now chiefly the Assyrian Church of the East (and a 1968 split called the Ancient Church of the East).

In 1994 John Paul II and Catholicos-Patriarch Mar Dinkha IV signed a Common Christological Declaration: both sides confess Christ as true God and true man, and they reject the old caricatures of Nestorian and monophysite.

• 1st–4th c. — Christianity in Mesopotamia and Persia
• 410 — Synod of Isaac organizes the Persian church
• 431 — Ephesus; lasting estrangement over Nestorius
• 781 — Xi’an stele; Church of the East in China
• 1552–1830s — Unions that form the Chaldean Catholic Church
• 1994 — Common Christological Declaration with Rome

Key figures and churches

Theodore of Mopsuestia and, later, Nestorius are the controversial teachers in Western memory. Living bodies include the Assyrian Church of the East, the Ancient Church of the East, and the Chaldean Catholic Church. India’s Saint Thomas Christians divided among East Syriac, West Syriac, and Catholic jurisdictions—ask which church you mean.

• Catholicos-Patriarch of the East (historic title)
• Assyrian Church of the East
• Ancient Church of the East (1968 split)
• Chaldean Catholic Church — in communion with Rome
• East Syriac Saint Thomas Christians in India

Beliefs and doctrines

The Church of the East confesses the Trinity, the Incarnation, baptism, Eucharist, and apostolic succession. Its Christology is strongly dyophysite: it stresses the integrity of the humanity and divinity. It did not receive Ephesus and later Western and Byzantine councils as its own. It does not accept Vatican I papal definitions.

The 1994 declaration allows Catholics to stop using “Nestorian” as a smear for this church. Remaining issues are communion, primacy, and some sacramental practice—not a cartoon of two Sons.

• East Syriac (Assyrian) liturgical and theological tradition
• Strong two-nature Christology; 1994 agreement with Rome
• Not Eastern Orthodox; not Oriental Orthodox
• No Vatican I papal supremacy
• Chaldean Catholics share the rite inside Catholic communion

Practices and worship

The Holy Qurbana of Addai and Mari is among the oldest Eucharistic anaphoras. Fasting, Syriac chant, and a married parish clergy with monastic bishops follow Eastern patterns. Diaspora parishes in the West are often neighbors to Chaldean Catholic churches; the rite can look similar while communion does not.

• East Syriac Qurbana (Addai and Mari)
• Syriac language and chant
• Married parish priests; monastic episcopacy
• Fasting calendar distinct from Latin practice

Scripture they emphasize

John 1:14 and the infancy narratives ground a full humanity. The school of Theodore read the distinction of natures tightly. Catholics share the texts and the confession that the Word became flesh; they disagree about which councils bind the whole Church and about Peter’s office.

• John 1:14 — Word became flesh

  “The Word became flesh, and lived among us. We saw his glory, such glory as of the one and only Son of the Father, full of grace and truth.”

• Luke 1:43 — Mother of my Lord

  “Why am I so favored, that the mother of my Lord should come to me?”

• Philippians 2:5–11 — true humanity and exaltation

  “Christ Jesus, existing in the form of God, didn’t consider equality with God a thing to be grasped, but emptied himself, taking the form of a servant, being made in the likeness of men. … Therefore God also highly exalted him.”

What to know before dialogue

Never collapse this church into Eastern Orthodoxy or into Coptic/Armenian Oriental Orthodoxy. Ask whether the person is Assyrian Church of the East, Ancient Church of the East, or Chaldean Catholic. Use the 1994 declaration against “Nestorian” slogans, then take remaining questions to councils, Christology, and primacy.

• Name the modern church body
• Distinguish from Eastern and Oriental Orthodoxy
• Do not use “Nestorian” as a nickname
• Chaldean Catholics are Catholic, not a third Orthodox family

Common misconceptions

Sources

Citations for this article. Browse the full bibliography to see every place each source is used across the library.

Debates & media

More debates and documents on the Resources page.

Related articles

Revision history

Who changed this page and when — newest first. Like a wiki edit log.