The Assyrian Church of the East

This church did not begin as a schism. It began outside the empire. While the churches of Rome, Constantinople, Alexandria and Antioch grew up inside Roman borders and argued in Greek and Latin, the church of Mesopotamia grew up in the Persian empire — Rome's rival and frequent enemy — and argued in Syriac. It traces itself to Thomas, Thaddeus and Bartholomew, and its ancient seat was Seleucia-Ctesiphon, the Persian capital on the Tigris. That single geographic fact explains almost everything that follows.

Because it lay outside Roman jurisdiction, it was never a participant in imperial church politics and could not be. When Persian shahs suspected their Christians of loyalty to the Roman enemy, the answer was persecution — the worst under Shapur II in the fourth century, in which tens of thousands died. To survive, the church declared its independence from the western patriarchates at the Synod of Markabta in 424 — seven years before Ephesus. It was already self-governing before the doctrinal quarrel ever reached it.

Babai the Great, and the formula that is not Nestorianism

The church's settled Christology was fixed not by Nestorius but by Babai the Great (d. 628) at the Synod of 612: Christ has two natures (kyane), two qnome, and one parsopa — one person, one prosopon, one Christ, one Son, one Lord. The load-bearing word is qnoma, and it has no clean Greek or English equivalent: it is not "person" (parsopa is person) and not quite "hypostasis" as the Greeks used it; it means something nearer a concrete individual instance of a nature. Greek ears heard "two hypostases" and concluded: two persons, two sons, two Christs. That is the whole quarrel, and it is a translation problem sitting on top of a jurisdictional one. See Field A.

The widest church on earth

And then, cut off from Christendom and under non-Christian rule the entire time, this church did something no other church has ever matched. It went east. Missionary monks followed the Silk Road; by the seventh century there were bishops in Herat, Samarkand and Merv; the church reached the Tang capital of Chang'an in 635 under a missionary the Chinese records call Alopen, and the emperor Taizong granted it official tolerance and had its scriptures translated for the imperial library. China became a metropolitan province of this church — Beth Sinaye — in the eighth century. A stele raised in 781 at Chang'an still survives, recording a century and a half of Christianity in China. There were sees in India, in Central Asia, among the Turks and Mongols. Around 1200 this was, by geography, the largest church in the world — and it had never had a Christian king, an army, or a state. See Field B.

The collapse

The fall was as total as the rise. The Mongol conversion to Islam under Ghazan (1295) turned a protector into a persecutor; Timur's campaigns at the end of the fourteenth century destroyed the church across Persia and Mesopotamia almost completely, driving the survivors into the mountains of Hakkari in what is now south-eastern Turkey. From a church spanning a continent it became a mountain people. Then in 1552 a disputed patriarchal succession split it again, and one line entered communion with Rome — the origin of the Chaldean Catholic Church, which today is considerably larger than the church it broke from. See Field C.

On the trunk of the faith this is ancient apostolic Christianity: the Trinity, the true deity and true humanity of Christ, the virgin birth, the atoning death, the bodily resurrection, the return of Christ, and the life of the world to come. It confesses the Nicene Creed without the filioque. The differences from our house are real, but they are not the ones the textbooks advertise.

Where it stands with the wider church

• Two councils only — Nicaea (325) and Constantinople (381). It receives neither Ephesus nor Chalcedon, which gives it the narrowest conciliar canon of any apostolic church on earth.
• It does not use the title Theotokos ("God-bearer") for Mary in the Greek sense, preferring "Mother of Christ our God and Saviour." The 1994 declaration with Rome explicitly recognized both formulations as legitimate expressions of the same faith. This was the original flashpoint at Ephesus.
• Seven sacraments, though enumerated differently from the Latin list — with Holy Leaven (Malka) and the Sign of the Cross counted among them, which is unique in Christendom.
• The Holy Leaven — the church holds that a portion of the original bread of the Last Supper has been carried forward and renewed in every eucharistic loaf since. No other church claims this.
• No icons and no statues in worship. The bare cross is venerated; images are not. On this — alone among the ancient churches — it stands nearer to us than to Constantinople or Rome.
• Married clergy at every level below bishop; bishops celibate. Historically, even the patriarchate was hereditary uncle-to-nephew from the fifteenth century until 1975 — an arrangement it has abandoned.
• Prayers for the dead and honour to the saints, but no defined purgatory and no doctrine of indulgences.

The Liturgy of Addai and Mari — the oldest prayer in Christendom

Its principal eucharistic prayer, the Anaphora of Addai and Mari, may be the oldest still in regular use anywhere in the Christian world, with roots reaching toward the third century or earlier. And it has a feature that has fascinated and unsettled liturgists for a century: it contains no Words of Institution — no "this is my body, this is my blood" in the consecratory formula.

In 2001 the Vatican, after study, formally recognized this anaphora as valid, on the ground that the institution narrative is present in the prayer's substance and euchological shape even where it is not quoted as a formula. That ruling is remarkable: it meant Rome accepted as a true eucharist a rite lacking the words Rome had taught for centuries were the form of the sacrament. For a house that argues about what Scripture requires and what tradition merely assumed, this is a case worth knowing.

The government of this church is episcopal and synodal, and it is very small. At the head is the Catholicos-Patriarch of the East — currently Mar Awa III, the 122nd holder of the office, seated at Ankawa in Erbil. Beneath him is a Holy Synod of eleven men in total: the patriarch, three metropolitans, and seven diocesan bishops. The entire governing hierarchy of a church with an unbroken line to the apostles fits around one table.

The Holy Synod as it stands (verified July 2026)

• Mar Awa III — Catholicos-Patriarch. Erbil.
• Mar Meelis Zaia — Metropolitan of Australia, New Zealand and Lebanon; Patriarchal Vicar.
• Mar Afram Athneil — Metropolitan of Syria.
• Mar Awgin Kuriakose — Metropolitan of India and the Southern Gulf.
• Mar Odisho Oraham — Bishop of Scandinavia and Germany.
• Mar Narsai Benjamin — Bishop of Iran, Armenia and Georgia.
• Mar Paulus Benjamin — Bishop of the Eastern United States.
• Mar Abrs Youkhanna — Bishop of Nohadra (Duhok) and Nineveh.
• Mar Benyamin Elya — Bishop of Victoria and New Zealand; Secretary General of the Holy Synod.
• Mar Awraham Youkhanis — Bishop of Western Europe; Chairman of the Patriarchal Commission for Inter-Church Relations.
• Mar Elia Isaac — Bishop of Baghdad.

The end of the hereditary patriarchate

From the fifteenth century until 1975 the patriarchate passed within one family, uncle to nephew — an arrangement adopted to hold the office secure through centuries with no state protection, and one that produced patriarchs consecrated as children. It ended when Mar Shimun XXIII, who had left the office to marry and then been restored, was assassinated in San Jose, California in 1975. The church moved to election by the Holy Synod, which is how Mar Dinkha IV (1976–2015), Mar Gewargis III (2015–2021) and Mar Awa III (2021– ) have been chosen. A church abandoned a five-century dynastic custom inside living memory — which is worth remembering next time someone tells you an ancient practice cannot be reformed.

Of every group in this hall, this one has held civil power for the shortest time — which is to say, never. Not once in nineteen centuries has the Church of the East governed a state, crowned a king, or commanded an army. It has been a minority under Zoroastrian Persia, under the Caliphates, under the Mongols, under the Ottomans, and under the modern republics of Iraq, Iran, Syria and Turkey. The throne-and-altar fusion this hall has warned against repeatedly was never available to it. That makes it the hall's cleanest natural experiment — and the results cut both ways.

Civil power — the ledger of a stateless church

• Under Persia: tolerated, then persecuted when suspected of Roman loyalty, then formally recognized once it declared independence from the western patriarchates in 424. Its autonomy was won as a loyalty proof, not a theological principle — and then it kept the autonomy for the next sixteen centuries.
• Under Islam: dhimmi status — protected, taxed, subordinate. In the Abbasid golden age its scholars were indispensable: East Syriac Christians led the translation of Greek philosophy, medicine and mathematics into Arabic, and physicians of this church served the caliphs. They held influence without ever holding power, which is a distinction this house should study carefully.
• Under the Mongols: its high-water mark. Several Mongol royal women were of this church; Rabban Bar Sauma, a monk from near Beijing, travelled as an envoy to Europe in the 1280s and gave communion to the King of England. And it ended in 1295 when the Ilkhanate converted to Islam.
• Under the Ottomans and after: the millet system, then catastrophe — 1915, 1933, and the long twentieth-century squeeze.

Wars without — the century of erasure

The modern history is a list of attempts to end this people. In 1915 the Sayfo killed a large share of the Assyrian, Syriac and Chaldean population alongside the Armenian Genocide, and drove the survivors out of Hakkari for good. In 1933, in the newly independent Iraq the community had trusted, the Simele massacre killed hundreds of Assyrian villagers and made the Patriarch a permanent exile. Under ISIS in 2014 the Nineveh Plains and Mosul — inhabited by these Christians since before Islam existed — were emptied in days. See Field D.

Wars within

Its internal fractures have all been about authority and custom, never about the gospel: the 1552 succession dispute that produced the Chaldean Catholic line, and the 1968 break over the calendar that produced the Ancient Church of the East. A church of a few hundred thousand people currently maintains two rival patriarchates over a question of dating. Field E.

You are most likely to meet this church in Chicago, Sydney, Modesto, Toronto, Stockholm or London rather than in Iraq — and what you walk into is a service in Syriac, a dialect of the Aramaic Christ spoke, in a building that will feel simultaneously more ancient and more austere than you expect.

What to expect

• The language. The Qurbana is chanted in Syriac; the sermon is usually in Syriac, Arabic or the local language. Much of the congregation is following by ear and habit, not by comprehension.
• No icons, no statues. The interior is plain by Eastern standards — a bare cross, not an iconostasis. Coming from a Reformed house, this will be the most familiar-feeling ancient liturgy you ever attend.
• Length and chant. Long, sung, antiphonal, with deacons answering the priest. Congregational standing is common.
• The Holy Leaven. The bread is made with the Malka — the leaven the church holds descends from the Last Supper itself. If you are shown it, understand you are being shown the community's dearest possession.
• A meal afterward, and the questions. This is a small, tight, mostly related community that has been asked to explain itself for a very long time. You will be asked who you are and why you came, and the question is not hostile — it is a survival reflex.
• The politics are in the room. The Assyrian national question, the villages, the 1915 memory and who now holds the land are not separate from church life here. Do not treat them as a distraction from the theology; for this community they are the same subject.

The state of this church in 2026 is an emergency, and saying anything softer would be dishonest. It is the smallest body in this hall, its homeland is emptying, and its survival as a territorial church in the land of its birth is a live question with perhaps one generation left to answer it.

• Iraq's Christian population has fallen to roughly 250,000, from something near 1.5 million in 2003 — an 85% collapse in two decades. That figure covers all Iraqi Christians; the Assyrian Church of the East is one share of a shrinking whole.
• The patriarchate has come home. After eighty years abroad — Cyprus, Chicago — the see is now at Ankawa in Erbil. That is a deliberate act of planting a flag in the homeland at the exact moment the homeland is emptying, and it should be read as the most significant strategic decision this church has made in a century.
• Its head is a Chicagoan. Mar Awa III was born in Chicago in 1975, took degrees from Loyola and the Pontifical Oriental Institute in Rome, and is the first Western-born Catholicos-Patriarch in the church's history — now governing from Erbil. The diaspora has begun supplying the homeland's leadership rather than the other way round.
• Ecumenically it is unusually busy for its size. Mar Awa III was received by Pope Leo XIV at the Vatican in October 2025; in February 2026 Mar Awraham Youkhanis met Patriarch Bartholomew in Constantinople; in May 2026 the patriarch attended the installation of the new Chaldean patriarch in Baghdad. A church of 400,000 is conducting the diplomacy of a much larger one.
• The Chaldean throne changed hands in 2026 amid scandal. Cardinal Louis Raphaël I Sako resigned on 9 March 2026 amid a financial and legal controversy; Mar Paul III Nona was elected 12 April and installed 29 May 2026. Because the Chaldean Church is this church's Roman counterpart and its largest neighbour, that succession changes the whole Iraqi Christian landscape. Field C.
• The 1968 breach is still open. Reunion talks with the Ancient Church of the East effectively stalled in 2022 with the election of Mar Yakoob III Danil to the rival throne. Field E.
• On artificial intelligence: nothing. No statement, no commission, no working document, no recorded remark by the patriarch. Field F.

This is the one dossier in the hall where the two-hundred-year forecast has to consider non-existence as a serious branch, and honesty requires putting it first rather than burying it.

Branch one — the diaspora church (most likely)

The likeliest outcome is that by 2226 the Assyrian Church of the East survives, at something like its present size or smaller, as a diaspora communion with a symbolic homeland presence: strong parishes in Australia, North America and Western Europe; the see perhaps still at Erbil, perhaps not; a small remnant in Iraq maintained partly as a witness and partly as a pilgrimage. The main threat on this branch is not persecution but assimilation — the fourth-generation problem, in which the Syriac goes first, then the endogamy, then the distinct identity, and the grandchildren are Episcopalians or nothing.

Branch two — reunion (real, and underrated)

The 1994 declaration with Rome removed the doctrinal barrier that stood for fifteen centuries. The Chaldean Catholic Church is the same people, the same rite, the same language, the same villages. The theological obstacle is essentially gone; what remains is the papacy and the memory of 1552. Over two centuries, under continued demographic pressure, some form of reunion or full communion between the Assyrian and Chaldean churches is a genuinely plausible outcome — and it would be the first healing of a great schism in Christian history. Watch this one. It is the likeliest place in the whole hall for an actual reconciliation to occur.

Branch three — extinction as a territorial church

If the Nineveh Plains do not stabilize, the homeland presence ends within a generation or two, and the church becomes wholly diasporic. This is not the end of the church, but it is the end of something — the last continuous Christian community speaking a form of the language of Christ in the land where it first believed. A house that keeps records should note that this could happen inside the lifetime of people now living.

There is no take. The file is empty, and this dossier will not fill it.

What can be said honestly

• The silence is itself the datum, and it is not indifference. Every other body in this hall that has an AI position also has seminaries, staff, budgets and a public affairs office. This church has eleven bishops and an existential demographic crisis. The absence measures institutional capacity, not conviction.
• Technology is in heavy practical use. Liturgical texts, Syriac fonts and language-teaching material are digitized and circulated online precisely because the diaspora is scattered and the young are losing the language. For this church the computer is not a theological question; it is the only surviving link between Sydney and Nohadra.
• The one real prize is textual. The Syriac manuscript corpus is enormous, under-read, and in some places physically endangered. Digitization, OCR and machine translation of Syriac are of far more consequence to this church than any doctrinal question about machine consciousness — and here the technology is straightforwardly a rescue operation.
• If asked, the resources they would reason from are ancient and clear: a firm Creator/creature line, a fiercely dyophysite instinct for keeping natures distinct and unconfused, and — alone among the ancient churches — a settled refusal of images in worship. That last one is the interesting thread, and it is why this file is worth reopening later. But that is our inference and is labelled as such.

Stated as they would state it, because "he that is first in his own cause seemeth just; but his neighbour cometh and searcheth him" (Proverbs 18:17).

• Never open with "Nestorian." Say "the Church of the East" or "the Assyrian Church of the East." If the history has to be discussed, name the label as a historical charge and say immediately that you know it is contested and that Rome signed a declaration in 1994 withdrawing it. Getting this wrong marks you instantly.
• Know the three things they are not. Not Oriental Orthodox (that is the opposite split). Not Syriac Orthodox (same language, opposite Christology). Not Chaldean Catholic (that is the half that went to Rome, and the sorest subject there is). Confusing the last one is the worst of the three.
• Lead with the reach, not with the ruin. Alopen, 635, the stele at Chang'an, Rabban Bar Sauma at the English king's table. They are used to being pitied and unused to being admired for the right thing.
• Say the dates that cost them. 1915. 1933. 2014. Knowing that Sayfo has a name earns more in one sentence than an hour of theology.
• Do not proselytize the persecuted. Western Protestants recruiting members out of an ancient church under mortal pressure is a scandal and is resented, rightly. Support, advocacy, prayer and material help are the duties here. Do not poach.
• Locate the disagreement honestly. It is Nestorius, the councils, the sacraments and tradition — not whether they divide Christ into two persons. Arguing that is fighting a war that ended by treaty in 1994.
• Mention the images. That an unbroken apostolic church has always worshipped without icons or statues is common ground almost no one knows about, and it will surprise them that you do.
• Ask about the manuscripts and the language work. It is the live, hopeful, practical subject in that community — and it is where a technically-minded house could actually be useful rather than merely sympathetic.
• Receive before you correct. A church that endured Shapur, Timur and ISIS without ever holding a sword has standing to teach a comfortable Protestant house about survival, and saying so is simply honest.

The documents that settle the argument — read these first

• The Common Christological Declaration between the Catholic Church and the Assyrian Church of the East (1994) — short, signed by John Paul II and Mar Dinkha IV, and the single most important text about this church. Read it before you read anything about it.
• The Guidelines for Admission to the Eucharist between the Chaldean Church and the Assyrian Church of the East (2001) — the Vatican ruling on the Anaphora of Addai and Mari. A remarkable document on form and substance in the sacraments.
• The Anaphora of Addai and Mari itself, in translation. Possibly the oldest eucharistic prayer still in use in the world.

The figures to know

• Babai the Great (d. 628) — fixed the church's actual Christology at the Synod of 612. The man the label ignores.
• Theodore of Mopsuestia (d. 428) — "the Interpreter," the church's revered exegetical father, condemned in the West. Loved here as Augustine is loved in the West.
• Isaac of Nineveh (7th c.) — the ascetical writer this church gave the whole Christian world. Read universally by Eastern Orthodox monks who have no idea he was a bishop of this church; the monastery Mar Awa III founded in California is named for him.
• Alopen (fl. 635) — the missionary who reached the Tang court. Field B.
• Rabban Bar Sauma (d. 1294) — the monk from near Beijing who travelled west as a Mongol envoy and gave communion to Edward I of England. The most extraordinary travel narrative in Christian history, and almost nobody in the West has read it.
• Mar Shimun XXIII (1908–1975) — the last hereditary patriarch, assassinated in California.
• Mar Dinkha IV (1935–2015) — the patriarch who signed the 1994 declaration.
• Mar Awa III (b. 1975) — the present Catholicos-Patriarch. Chicago-born; doctorate from the Pontifical Oriental Institute; author of Mysteries of the Kingdom (2011).

The scholars

• Sebastian Brock — the foremost Syriacist of the age, Oxford. Visited by Mar Awraham Youkhanis in March 2026. If you read one modern scholar on Syriac Christianity, read Brock.
• David Wilmshurst — The Martyred Church: A History of the Church of the East. The standard single-volume narrative.
• Christoph Baumer — The Church of the East: An Illustrated History of Assyrian Christianity. The maps alone justify it, and the maps are the argument of Field B.
• Philip Jenkins — The Lost History of Christianity. The most accessible account of how a church this large disappeared from Western memory.