The Church of the East: Was It Really Nestorian?

For more than a thousand years, a church whose bishops sat in Persia, India and China was known in Greek and Latin books by one word: "Nestorian." The label suggested a sect founded by Nestorius, the archbishop of Constantinople deposed at the Council of Ephesus in 431, and a theology that split Christ into two sons. Most Christians still assume it is simply the church's name.

Its members call it the Church of the East. Its main heirs today are the Assyrian Church of the East and the Ancient Church of the East, while the Chaldean Catholic and Syro-Malabar churches keep its East Syriac heritage in communion with Rome. Syriac scholars, Catholic dialogue partners and the church itself now argue that "Nestorian" is a misnomer. Orthodox Christians, who confess Ephesus as the Third Ecumenical Council, should ask honestly whether that is true and what follows if it is.

In brief

The Church of the East grew up in the Persian (Sasanian) Empire, outside the Roman world where the great councils met. It accepted Nicaea in 410 and declared its independence from "western" bishops in 424, before the Nestorian controversy began. Its official Christology, first stated in 486, follows Theodore of Mopsuestia, not Nestorius, whose main work reached Syriac only around 540. Its synods confess one Son, one Lord and one object of worship. But the church never accepted Ephesus, honors Nestorius as a saint, and from 612 made "two natures and two qnome" its official teaching, a formula that sounds like two persons to Greek ears although the Syriac qnoma does not mean "person." The label "Nestorian" is therefore misleading, as the leading Syriac scholars say, yet the differences are real. Rome signed a common declaration on Christ with the Assyrian Church in 1994; no Eastern Orthodox church has done so. Orthodoxy still holds Ephesus and the Fifth Council as binding, while loving a Church of the East monk, St Isaac the Syrian, as a spiritual teacher.

Thesis: The Church of the East was not "Nestorian" in the sense the word usually carries, because it never taught two Sons, but its refusal of Ephesus and its veneration of Nestorius and Theodore are real obstacles that Orthodoxy cannot remove by redefining a label.

A church beyond the empire

Christianity was present east of the Euphrates by the early third century; Sebastian Brock, a leading scholar of Syriac Christianity, notes that a pupil of Bardaisan (d. 222) lists Christians in Parthia, Media and neighboring lands.¹ Once Rome's emperors became Christian, the Persian shahs suspected their Christian subjects, and Shapur II's persecution, which probably began in 341 and continued intermittently until 379, filled the Persian martyr acts.²

In 410 a synod at Seleucia-Ctesiphon under Isaac, its bishop (later sources call him catholicos), convened by Shah Yazdgard I at the prompting of the Roman envoy Bishop Marutha, accepted the creed and canons of Nicaea.³ In 424 a synod under the catholicos Dadisho affirmed the independence of Seleucia-Ctesiphon from the "western bishops."⁴ That was a decision about jurisdiction, taken four years before Nestorius became a bishop.

The church's theology came through a school. Persian students at the "School of the Persians" in Edessa absorbed Theodore of Mopsuestia's writings, translated into Syriac there from the 420s and 430s; when Emperor Zeno closed the school in 489, its staff moved to Nisibis in Persia.⁵ As Brock summarizes, news of the Greek debates "would come primarily by way of the Persian School of Edessa," so the church's language was "essentially Antiochene, and specifically Theodoran."⁶ Ephesus and Chalcedon were Roman imperial councils that Persian bishops did not attend, and from the Church of the East's viewpoint they "were far from being truly ecumenical."⁷ Orthodox readers will not accept that conclusion, but it explains why this church never saw itself as a breakaway from Constantinople.

What the Persian synods actually said

The best evidence is the Synodicon Orientale, the synodal acts edited by J.-B. Chabot in 1902, whose Christological statements Brock translated in 1985.⁸ Here the church speaks for itself.

The synod of 486

The first statement after Ephesus and Chalcedon came from a synod under the catholicos Akakios in 486. It confesses "the two natures, of the divinity and of the humanity," forbids "mixture, mingling or confusion," and gathers them "to a single Lordship and to a single (object of) worship" because of their "perfect and inseparable conjunction." It anathematizes anyone who attributes suffering to the divinity or does not preserve, "with respect to the union (hdayuta) of the prosopon of our Saviour, a confession of perfect God and perfect Man."⁹

This is strong two-nature language with an obvious fear of saying that God suffered. Brock judges that it "markedly belongs to the Antiochene tradition of Christology, but it can in no way be described as openly 'Nestorian'."¹⁰ "Perfect God and perfect Man" also echoes the Formula of Reunion of 433, which grew out of John of Antioch's synod, was accepted by Cyril of Alexandria, and confessed "the union of the two natures" in one Christ and the Virgin as Mother of God.¹¹

The assembly of 612 and the word qnoma

In 612 Shah Khosrau II ordered a disputation with the Syriac Orthodox. The bishops confessed "one person (prosopon) our Lord Jesus Christ, the Son of God," "perfect God and perfect Man," but in reply to their opponents wrote that "Christ is two natures and two qnome," one "in the single prosopon of Sonship."¹² Luise Abramowski concludes that this document "made two qenome in the one Christ the official teaching of the Church of the East."¹³

Everything turns on qnoma, the standard Syriac rendering of the Greek hypostasis. To Greek ears "two qnome" means two hypostases, which Chalcedon rejected. Brock argues the words did not match: for East Syriac writers kyana ("nature") is generic, while a qnoma is "an individual manifestation of a kyana," so the two qnome are the concrete divinity and concrete humanity of the one Christ. Translating qnoma as "person" here, he writes, "is to be deplored," and none of these texts uses the truly Nestorian formula of two prosopa.¹⁴ In them "there is never any doubt that God the Word, in his humanity, suffered and died: there is no question of two subjects."¹⁵

{{strong: The official Christology of the Church of the East, from 486 onward, confesses one Son and one object of worship and never teaches two persons or two Sons.}} Whether "two qnome" can be reconciled with Chalcedon's "one hypostasis" is a harder question.

Theodore, Nestorius and Babai

Theodore of Mopsuestia

The church's great teacher is Theodore of Mopsuestia (c. 350 to 428), "the Interpreter." He died in peace with the Church; only after Ephesus was he cast as the originator of Nestorianism.¹⁶ In his homilies on the Creed he calls the humanity a "temple" in which the Word dwells, yet argues against counting two Sons: since only one is Son and Lord by nature, "we hold that there is one Son only."¹⁷ The temple image is biblical: "But He was speaking of the temple of His body" (John 2:21, NKJV). Even the Formula of Reunion speaks of the Word uniting to himself the temple taken from the Virgin.¹⁸

The Orthodox verdict came in 553, when the Fifth Ecumenical Council anathematized anyone who defends "the impious Theodore of Mopsuestia, who has said that the Word of God is one person, but that another person is Christ."¹⁹ The council judged him from excerpts gathered by opponents, and scholars still debate their fairness, but the condemnation stands in Orthodoxy as conciliar.

Nestorius himself

Nestorius became archbishop of Constantinople in 428. When his presbyter Anastasius preached against calling Mary Theotokos ("God-bearer"), Nestorius backed him and proposed "Christotokos" as a compromise.²⁰ André de Halleux argued that Nestorius later accepted Theotokos in a sermon of 7 December 430, as Abramowski reports.²¹ Cyril answered that the Fathers "ventured to call the Holy Virgin, the Mother of God, not as if the nature of the Word or his divinity had its beginning from the Holy Virgin," but because the Word united to himself the flesh born of her.²² Elizabeth had already greeted "the mother of my Lord" (Luke 1:43, NKJV).

Ephesus deposed Nestorius in 431, but irregularly: Cyril's party opened the council after waiting sixteen days, before John of Antioch's bishops arrived, and John's group held a rival council.²³ The historian Socrates, no admirer of Nestorius's learning, read his works and concluded: "I cannot then concede that he was either a follower of Paul of Samosata or of Photinus, or that he denied the Divinity of Christ: but he seemed scared at the term Theotocos, as though it were some terrible phantom."²⁴

For the Church of the East, Nestorius was more symbol than teacher. His Book of Heraclides reached Syriac only around 540, as Brock wrote in summarizing a paper by the Assyrian bishop Mar Bawai Soro, "over half a century after the 'official adoption of Nestorianism' by the church of the East in 486, as all too many western textbooks misleadingly would have it."²⁵ Brock calls talk of a "nestorianization" of the Persian church "misleading in the extreme," a product of "the rhetorical hyperbole of the theological opponents of the Church of the East, who regularly labelled anything to do with Theodore as, by implication, Nestorian."²⁶

Babai the Great

The church's most systematic theologian, Babai the Great (c. 551 to 628), wrote the Book of the Union, which "remains a fundamental statement of the Christology of the Church to this day"; a surviving excerpt of his argues that two natures imply two qnome.²⁷ Brock notes that Babai held "the strictest dyophysite position, openly rejecting the Chalcedonian position," and, unusually, drew on Nestorius's Book of Heraclides.²⁸ Here those who defend the old label have their best point: after Babai, the church's official language moved away from Chalcedon.

Where the label came from

"Nestorian" began as an accusation. The Syriac Orthodox held that the Persian church was "nestorianized" in the late fifth century, and because they saw Theodore as implying Nestorius, "the epithet 'Nestorian' was misleadingly applied."²⁹ In the 612 dispute their side asked whether "the Nestorians" had abandoned the faith.³⁰ The Gorgias Encyclopedic Dictionary of the Syriac Heritage, in an entry by Brock and James Coakley, says the church "was misleadingly labelled as 'Nestorian' by its theological opponents."³¹ Brock's best-known essay on the subject is titled "The 'Nestorian' Church: A Lamentable Misnomer" (1996).³²

One complication must be admitted. Church of the East writers have sometimes used the label themselves. At a 1994 Vienna consultation, Mar Aprem Mooken, a Church of the East metropolitan in India who said in the discussion that his statements were deliberately blunt, wrote that "this Church considers Nestorius as a saint," that its formula is "the prosopic union rejecting the formula of hypostatic union accepted by both Catholics and the Eastern Orthodox Churches," and that "A Nestorian is an orthodox without theotokos." He also insisted, "this is not a Church founded by Nestorius."³³

From Persia to China: the Xi'an stele

The Church of the East was the great missionary church of Asia, reaching China and south India before plague, oppression and massacres from the fourteenth century onward diminished it.³⁴ Its most famous monument is a stele unearthed at Xi'an in the 1620s (sources give 1623 or 1625).³⁵ {{very-strong: The stele is dated 781 and records, in Chinese with Syriac names, the arrival of a missionary from the West in 635 and the growth of the "Illustrious Religion" (jingjiao) under the Tang emperors.}}

In the translation in Charles Horne's 1917 collection, the monk Olopun reaches the capital in 635, the sacred books are translated in the imperial library, and the emperor "gave special orders for its dissemination."³⁶ The text speaks of a virgin giving birth "to the Holy One in Syria," of baptism, the cross, worship facing east, and monks who "do not keep slaves," and its Syriac lines name the patriarch and the clergy who erected it.³⁷ It uses Chinese and Buddhist-flavored vocabulary rather than a technical creed. Some European critics once called it a Jesuit forgery; Michael Keevak has shown how those debates reflected European agendas, and they were resolved by the early twentieth century.³⁸

The 1994 Common Christological Declaration

On 11 November 1994 Pope John Paul II and Catholicos-Patriarch Mar Dinkha IV declared that Christ's "divinity and his humanity are united in one person, without confusion or change, without division or separation," and that "The humanity to which the Blessed Virgin Mary gave birth always was that of the Son of God himself." The Assyrian Church prays to Mary as "the Mother of Christ our God and Saviour," Catholics as "the Mother of God," and both "recognize the legitimacy and rightness of these expressions of the same faith." Past divisions "were due in large part to misunderstandings."³⁹

In 2001 Rome accepted the ancient Anaphora of Addai and Mari, which lacks a continuous institution narrative, and called the Assyrian Church "a true particular Church, built upon orthodox faith and apostolic succession."⁴⁰ In 2024 Pope Francis added St Isaac of Nineveh to the Roman Martyrology, and in 2025 Pope Leo XIV spoke of "reaching agreement on Christological faith and thus resolving a 1,500-year-old controversy."⁴¹ The declaration says "one person" and avoids qnoma and hypostasis, settling the faith without settling the vocabulary. It also never mentions Ephesus, which, Brock reported in 1994, the Church of the East "has never accepted."⁴²

What the Orthodox Church says today

Dogma. Orthodoxy confesses Ephesus (431) and Constantinople II (553) as ecumenical councils. Mary is Theotokos because the one she bore is God the Word incarnate, and the teaching attributed to Theodore in 553 is condemned. The councils are received as one inheritance, not a menu (see how Orthodoxy recognizes ecumenical councils and what the seven councils decided).

Practice. The Russian Church, at least, treated Church of the East Christians as Christians in error. When Mar Yonan, a Church of the East bishop from Urmia in Persia, was received into the Russian Church in 1898, he was asked, according to a later account, "Do you renounce the errors of your forebears, and the errors of the Nestorian faith?" He was received with his clergy and served on as a bishop, and the Russian Synod founded a mission in Urmia that lasted until 1918.⁴³ The Russian Church demanded a renunciation while treating his orders as real.

Orthodox monks have also loved a writer from this church for over a thousand years. St Isaac the Syrian was made bishop of Nineveh in the late 670s by the Church of the East's catholicos Gewargis.⁴⁴ His discourses were translated into Greek at the Monastery of St Sabas in the ninth century, and Brock calls him "a much-loved monastic author in the Orthodox world." The Greek kept his title, yet quotations from Theodore were reassigned to John Chrysostom and Gregory of Nazianzus.⁴⁵ The Orthodox Church in America commemorates him on 28 January,⁴⁶ though Brock notes he "was never formally recognised as a saint in any liturgical calendar in earlier periods."⁴⁷

Where things stand. We found no published Christological agreement between any Eastern Orthodox church and the Assyrian Church of the East comparable to the 1994 declaration. There have been friendly contacts, such as Mar Dinkha IV's 2014 visit to the Russian Orthodox Church at Patriarch Kirill's invitation.⁴⁸ The 1994 Pro Oriente consultation on this church's theology brought together Catholic, Oriental Orthodox and Assyrian theologians, with no Eastern Orthodox church represented.⁴⁹ For Orthodoxy, the word "Nestorian" is a matter of historical judgment and charity; communion is a matter of dogma, and that question remains open. For background, see The Identity of Jesus and what Chalcedon defined.

The strongest objections

"They venerate Nestorius and reject Ephesus, so the label fits."

This Orthodox objection is partly right. The church honors Diodore, Theodore and Nestorius, celebrated by its poet Narsai as the "Three Doctors," never received Ephesus, and made "two qnome" official in 612. A church that rejects an ecumenical council cannot be in communion with Orthodoxy while it does so. But "Nestorian" usually means teaching two Sons, and the synods condemn that: the synod of 554 anathematized anyone "who considers or speaks of two Christs, or two Sons."⁵⁰ Still, the concern goes beyond two Sons. Cyril's second letter, which Ephesus received, warned that it will not "avail to a sound faith to hold, as some do, an union of persons," and Mar Aprem describes his church's formula as a "prosopic union."⁵¹ The fair statement is that the Church of the East rejects Ephesus without holding the two-Sons doctrine the label implies.

"Ephesus was a power play, so Orthodoxy should drop it."

The irregularities are real, as the council's own letters show. But Orthodoxy receives Ephesus for its teaching, not its procedure, and that teaching was confirmed when the Antiochenes and Cyril agreed in 433 and when Chalcedon reaffirmed Theotokos in 451. Even Socrates, who cleared Nestorius of denying Christ's divinity, thought Theotokos was the ancient faith.⁵²

"Rome has settled this. Why hasn't Orthodoxy?"

Rome's achievement is genuine, and its method of looking past formulas to the faith they express deserves Orthodox attention. But Orthodoxy acts through synods and the consent of its local churches, with no single authority to sign for all, and the Orthodox churches would have to decide together whether an agreement that is silent about Ephesus is enough.

"Two qnome means two hypostases."

This is the classic Oriental Orthodox objection; Coptic Orthodox objections kept the Assyrian Church out of membership of the Middle East Council of Churches, Brock reported in 1994.⁵³ The reply is linguistic: if qnoma means an individual instance of a nature, "two qnome" is closer to Chalcedon's two natures, each keeping its properties, than to two persons, and the texts' "one prosopon," "one Son" and "single Lordship" support that. Not every scholar thinks the gap is only verbal, and Babai's open rejection of Chalcedon shows the church's own theologians thought more was at stake.

What we can say confidently

• The Church of the East accepted Nicaea in 410 and declared independence from western bishops in 424, before the Nestorian controversy.
• Its official Christology from 486 follows Theodore, confesses one Son and one object of worship, and condemns two Christs or two Sons.
• Nestorius's main work reached Syriac only around 540, so the church did not adopt "Nestorianism" in 486.
• "Nestorian" began as a polemical term, and leading Syriac scholars regard it as misleading.
• The church never accepted Ephesus, honors Nestorius as a saint, and made "two natures and two qnome" official in 612.
• The Xi'an stele of 781 is a genuine witness to its mission in Tang China.
• Rome and the Assyrian Church signed a Christological declaration in 1994; no comparable Orthodox agreement has been published.

What remains disputed

• {{debated: Whether the formula of two qnome in one prosopon is fully compatible with Chalcedon's one hypostasis in two natures, or differs in substance as well as vocabulary.}}
• How fairly the excerpts condemned in 553 represent Theodore's own teaching.
• How far Nestorius himself can be called orthodox; some scholars, including the Greek Orthodox historian Milton Anastos, have defended him, and others have not.
• Whether communion could be restored if the Church of the East received the councils' teaching without their anathemas of persons.

Conclusion

The Church of the East was not "Nestorian" in the sense the word suggests. Its bishops confessed one Lord Jesus Christ, true God and true man, who suffered in his humanity for our salvation, and they did so in Syriac, outside the empire, with Theodore as teacher and a vocabulary the Greek Church had left behind. The label was largely a weapon, and Orthodox Christians should stop using it as a neutral description.

But charity about labels is not agreement in faith. The Orthodox Church confesses with Ephesus that the Virgin is Theotokos because her Son is God the Word, and it holds the councils as one inheritance. The Church of the East has honored Nestorius and refused that council for fifteen centuries, and goodwill does not make that disappear.

There is still room for hope. Orthodox monks have prayed with St Isaac of Nineveh for a thousand years, and Assyrian Christians in Iraq, Iran and Syria have suffered for Christ in our own time. A church that carried the name of Jesus from Mesopotamia to China deserves to be described accurately, prayed for warmly and met in patient dialogue. For more on Christian divisions, see the Christian family tree and the Church Fathers Explorer.

Notes

1. Sebastian Brock, "The Church of the East in the Sasanian Empire up to the Sixth Century and its Absence from the Councils in the Roman Empire," in Syriac Dialogue: First Non-Official Consultation on Dialogue within the Syriac Tradition (Vienna: Pro Oriente, 1994), 70-71. Back
2. Brock, "Church of the East in the Sasanian Empire," 71-72. Back
3. Brock, "Church of the East in the Sasanian Empire," 73-74; Sebastian Brock, "The Christology of the Church of the East in the Synods of the Fifth to Early Seventh Centuries: Preliminary Considerations and Materials," in George Dragas, ed., Aksum-Thyateira: A Festschrift for Archbishop Methodios of Thyateira and Great Britain (London: Thyateira House, 1985), 126. Back
4. Brock, "Church of the East in the Sasanian Empire," 75. Back
5. Brock, "Church of the East in the Sasanian Empire," 73, 75. Back
6. Brock, "Christology of the Church of the East," 130. Back
7. Brock, "Christology of the Church of the East," 130. Back
8. J.-B. Chabot, ed., Synodicon Orientale (Paris, 1902); English translations in Brock, "Christology of the Church of the East," 133-42. Back
9. Synod of 486, Synodicon Orientale 54-55, trans. Brock, "Christology of the Church of the East," 133-34. Back
10. Brock, "Christology of the Church of the East," 126. Back
11. Formula of Reunion (433), as quoted in John Paul II, General Audience, 16 March 1988 (Italian text, citing Denzinger 272); on its origin in John of Antioch's synod and Cyril's acceptance, Luise Abramowski, "The History of Research into Nestorius," in Syriac Dialogue (1994), 59, 61; on the echo in 486, Adelbert Davids, "Is the Theology of the Church of the East Nestorian?" in the same volume, 139 n. 27. Back
12. Assembly of bishops of 612, Synodicon Orientale 564-67 and 575, trans. Brock, "Christology of the Church of the East," 141-42; on the occasion, ibid., 127. Back
13. Luise Abramowski, "The History of Research into Nestorius," in Syriac Dialogue (1994), 65. Back
14. Brock, "Christology of the Church of the East," 131. Back
15. Brock, "Christology of the Church of the East," 131. Back
16. Lucas Van Rompay, "Theodore of Mopsuestia," in Sebastian P. Brock, Aaron M. Butts, George A. Kiraz and Lucas Van Rompay, eds., Gorgias Encyclopedic Dictionary of the Syriac Heritage, electronic edition (Beth Mardutho). Back
17. Theodore of Mopsuestia, Commentary on the Nicene Creed, Homily 8, trans. Alphonse Mingana, Woodbrooke Studies 5 (Cambridge: Heffer, 1932), 90-91. Back
18. Formula of Reunion (433), in John Paul II, General Audience, 16 March 1988 (Denzinger 272). Back
19. Second Council of Constantinople (553), Capitula, anathema 12, trans. Henry R. Percival, NPNF2 vol. 14. Back
20. Socrates Scholasticus, Ecclesiastical History 7.32, trans. A. C. Zenos, NPNF2 vol. 2; George A. Bevan, "Nestorius," in Gorgias Encyclopedic Dictionary of the Syriac Heritage, electronic edition. Back
21. Abramowski, "The History of Research into Nestorius," 61, summarizing André de Halleux. Back
22. Cyril of Alexandria, Second Letter to Nestorius, in Council of Ephesus, trans. Henry R. Percival, NPNF2 vol. 14. Back
23. Synodal letter of the Council of Ephesus on John of Antioch, NPNF2 vol. 14; Bevan, "Nestorius," GEDSH. Back
24. Socrates, Ecclesiastical History 7.32, NPNF2 vol. 2. Back
25. Sebastian Brock, "PRO ORIENTE Consultation 1994: Orthodoxy and Catholicity in the Syriac Tradition," in Syriac Dialogue (1994), 225, summarizing Mar Bawai Soro's paper; on the date of the translation, Brock, "Christology of the Church of the East," 127. Back
26. Brock, "Christology of the Church of the East," 130. Back
27. Sebastian Brock, "Babai the Great," in Gorgias Encyclopedic Dictionary of the Syriac Heritage, electronic edition (the excerpt is in Abramowski and Goodman, A Nestorian Collection of Christological Texts, 1972). Back
28. Brock, "Christology of the Church of the East," 128, 132. Back
29. Brock, "Christology of the Church of the East," 126 n. 4. Back
30. Brock, "Christology of the Church of the East," 127. Back
31. Sebastian P. Brock and James F. Coakley, "Church of the East," in Gorgias Encyclopedic Dictionary of the Syriac Heritage, electronic edition. Back
32. Sebastian P. Brock, "The 'Nestorian' Church: A Lamentable Misnomer," Bulletin of the John Rylands University Library of Manchester 78, no. 3 (1996): 23-35. Back
33. Mar Aprem G. Mooken, "Is the Theology of the Church of the East Nestorian?" in Syriac Dialogue (1994), 150; on his "blunt statements," the discussion record, 152. Back
34. Brock and Coakley, "Church of the East," GEDSH. Back
35. Michael Keevak, The Story of a Stele: China's Nestorian Monument and Its Reception in the West, 1625-1916 (Hong Kong: Hong Kong University Press, 2008), 5, as quoted in Franklin Perkins's review, Journal of Chinese Studies 49 (2009): 465-70. Some sources date the find to 1623. Back
36. "Nestorian Tablet: Eulogizing the Propagation of the Illustrious Religion in China," in Charles F. Horne, ed., The Sacred Books and Early Literature of the East, vol. 12, Medieval China (New York: Parke, Austin, and Lipscomb, 1917), 381-92 (Internet East Asian History Sourcebook). Back
37. Horne, ed., "Nestorian Tablet." Back
38. Keevak, Story of a Stele, as summarized in Perkins's review, Journal of Chinese Studies 49 (2009): 465-70. Back
39. John Paul II and Mar Dinkha IV, Common Christological Declaration between the Catholic Church and the Assyrian Church of the East, 11 November 1994 (vatican.va). Back
40. Pontifical Council for Promoting Christian Unity, Guidelines for Admission to the Eucharist between the Chaldean Church and the Assyrian Church of the East, 20 July 2001 (christianunity.va). Back
41. Dicastery for Promoting Christian Unity, "Inclusion of Isaac of Nineveh in the Roman Martyrology," 11 November 2024; Leo XIV, Address to Mar Awa III and the Joint Commission, 27 October 2025 (vatican.va). Back
42. Brock, "PRO ORIENTE Consultation 1994," 225. Back
43. Michael Woerl, "Abun Mar Elia (Abraham) (1858-1928) of Supurgansk and Urmia," ROCOR Studies (2015), quoting earlier accounts of the 1898 reception. Back
44. Sebastian Brock, "St Isaac the Syrian: from Tehran to Moni Iviron, Mount Athos," Kulturní studia 26, no. 1 (2026): 34; Dicastery for Promoting Christian Unity, "Inclusion of Isaac of Nineveh" (2024), giving 676 to 680. Back
45. Brock, "St Isaac the Syrian," 33, 35. Back
46. Orthodox Church in America, "Saint Isaac the Syrian, Bishop of Nineveh," Lives of the Saints, 28 January (oca.org). Back
47. Brock, "St Isaac the Syrian," 41. Back
48. Assyrian Church of the East News, "Catholicos-Patriarch Meets with Russian Orthodox Hierarch Metropolitan Hilarion in Moscow" (4 June 2014) and "Delegation of the Assyrian Church of the East Visits Russia and Armenia" (11 August 2015). Back
49. Brock, "PRO ORIENTE Consultation 1994," 224, listing the churches represented. Back
50. Synod of 554, Synodicon Orientale 97-98, trans. Brock, "Christology of the Church of the East," 135; on Narsai's homily on the Three Doctors, ibid., 128. Back
51. Cyril of Alexandria, Second Letter to Nestorius, NPNF2 vol. 14; Mooken, "Is the Theology of the Church of the East Nestorian?" 150. Back
52. Socrates, Ecclesiastical History 7.32, NPNF2 vol. 2; Formula of Reunion (433), Denzinger 272. Back
53. Brock, "PRO ORIENTE Consultation 1994," 224. Back

Bibliography

Primary sources

• Chabot, J.-B., ed. Synodicon Orientale. Paris, 1902. Christological statements translated in Brock, "The Christology of the Church of the East" (below).
• Council of Ephesus (431) and Second Council of Constantinople (553). In The Seven Ecumenical Councils, trans. Henry R. Percival. NPNF2 vol. 14. newadvent.org.
• Socrates Scholasticus. Ecclesiastical History, trans. A. C. Zenos. NPNF2 vol. 2. newadvent.org.
• Theodore of Mopsuestia. Commentary of Theodore of Mopsuestia on the Nicene Creed, trans. Alphonse Mingana. Woodbrooke Studies 5. Cambridge: Heffer, 1932.
• "Nestorian Tablet" (Xi'an stele, 781). In Charles F. Horne, ed., The Sacred Books and Early Literature of the East, vol. 12. New York: Parke, Austin, and Lipscomb, 1917.
• John Paul II and Mar Dinkha IV. Common Christological Declaration between the Catholic Church and the Assyrian Church of the East. 11 November 1994.
• Pontifical Council for Promoting Christian Unity. Guidelines for Admission to the Eucharist between the Chaldean Church and the Assyrian Church of the East. 20 July 2001.
• Formula of Reunion (433). Quoted in John Paul II, General Audience, 16 March 1988 (Denzinger 272).
• Dicastery for Promoting Christian Unity, "Inclusion of Isaac of Nineveh in the Roman Martyrology," 11 November 2024; Leo XIV, Address to His Holiness Mar Awa III and the Joint Commission for Theological Dialogue, 27 October 2025.
• The Holy Bible, New King James Version.

Orthodox and patristic sources

• Orthodox Church in America. "Saint Isaac the Syrian, Bishop of Nineveh." Lives of the Saints, 28 January.
• Woerl, Michael. "Abun Mar Elia (Abraham) (1858-1928) of Supurgansk and Urmia." ROCOR Studies, 2015.

Other scholarship

• Brock, Sebastian. "The Christology of the Church of the East in the Synods of the Fifth to Early Seventh Centuries: Preliminary Considerations and Materials." In George Dragas, ed., Aksum-Thyateira: A Festschrift for Archbishop Methodios of Thyateira and Great Britain, 125-42. London: Thyateira House, 1985.
• Brock, Sebastian P. "The 'Nestorian' Church: A Lamentable Misnomer." Bulletin of the John Rylands University Library of Manchester 78, no. 3 (1996): 23-35.
• Brock, Sebastian. "St Isaac the Syrian: from Tehran to Moni Iviron, Mount Athos." Kulturní studia 26, no. 1 (2026): 32-43.
• Brock, Sebastian P., Aaron M. Butts, George A. Kiraz and Lucas Van Rompay, eds. Gorgias Encyclopedic Dictionary of the Syriac Heritage. Electronic edition, Beth Mardutho. Entries "Church of the East" (Brock and Coakley), "Babai the Great" (Brock), "Nestorius" (Bevan), "Theodore of Mopsuestia" (Van Rompay).
• Syriac Dialogue: First Non-Official Consultation on Dialogue within the Syriac Tradition. Vienna: Pro Oriente, 1994. Papers by Sebastian Brock, Luise Abramowski and Mar Aprem G. Mooken, and Brock's report on the consultation.
• Keevak, Michael. The Story of a Stele: China's Nestorian Monument and Its Reception in the West, 1625-1916. Hong Kong: Hong Kong University Press, 2008. Consulted through Franklin Perkins's review, Journal of Chinese Studies 49 (2009): 465-70.

Sources from the tradition being discussed

• Mar Aprem G. Mooken. "Is the Theology of the Church of the East Nestorian?" In Syriac Dialogue, 142-52. Vienna: Pro Oriente, 1994.
• Assyrian Church of the East News (news.assyrianchurch.org). Reports of 4 June 2014 and 11 August 2015 on contacts with the Moscow Patriarchate.