Tradition

The Chaldean Tradition

The East Syriac liturgical family of Mesopotamia: the Chaldean and Syro-Malabar Catholics, the Assyrian Church of the East, and the Ancient Church of the East.

Last verified 2026-09-21

In Brief

The Chaldean Tradition is the East Syriac liturgical family formed in the Syriac Christianity of Mesopotamia and Persia — the eucharistic life of the Church of the East, whose anaphora par excellence is the ancient Anaphora of the Apostles Addai and Mari. The Catholic Church's Eastern code names this family "Chaldaea" among the traditions of the Churches sui iuris1. It is prayed today by two Catholic Churches — the Chaldean Catholic Church and the Syro-Malabar Church of India — and, outside Catholic communion, by the Assyrian Church of the East and the Ancient Church of the East.

Its marks are Syriac as the liturgical language, with Malayalam alongside it in India2; leavened bread, of which the Assyrian Church's own history speaks as the leavened loaf3; and the anaphora of Addai and Mari, used through most of the year, with those of Theodore and of Nestorius for their appointed seasons4. The Chaldean, Syro-Malabar and Assyrian Churches keep the Gregorian calendar; the Ancient Church of the East keeps the Julian5,6,7.

The classical form of Addai and Mari carries no coherent narrative of the Institution: the 1890 Urmia text, read in Syriac, prints none, the narrative appearing in the examined copy only as a separately printed leaf bound in8. A long Holy See study concluded on 17 January 2001 that the anaphora "can be considered valid", a decision John Paul II approved; the Guidelines of 20 July 2001 explain the institution words as present "not in a coherent narrative way and ad litteram, but rather in a dispersed euchological way"9.

The Chaldean Catholic Church is a patriarchal Church centred on Baghdad, led since April 2026 by Patriarch Polis III Nona5,10. The Syro-Malabar Church, a major-archiepiscopal Church under Major Archbishop Raphael Thattil11, is the largest of the family, numbering some 4.9 million faithful12. The Assyrian Church of the East, led by Catholicos-Patriarch Mar Awa III from Erbil6, and the Ancient Church of the East, formed in 1968 over the calendar and the fasting rules7, complete the tradition's four Churches.

The older label "Nestorian" is avoided here: it is doctrinal rather than liturgical13. The 1994 Common Christological Declaration between John Paul II and Mar Dinkha IV14 and the 2001 Guidelines — which regulate eucharistic admission, in necessity, between the Chaldean and Assyrian faithful exclusively — frame the tradition's ecumenical standing today9.

Member Rites & Uses

Churches

Catholic Churches sui iuris

  • Syro-Malabar ChurchMajor archiepiscopal Church15
  • Chaldean Catholic ChurchPatriarchal Church5

The Assyrian Church of the East and the Ancient Church of the East, though not in Catholic communion, share this one East Syriac Qurbana; Rome's 2001 study notes that the Chaldean Church and the Assyrian Church of the East 'still share' their liturgical heritage4.

Other Churches sharing the tradition

  • Assyrian Church of the EastThe continuation of the Shim'un patriarchal line; the 2021 Holy Synod affirmed Erbil as the patriarchal diocese6
  • Ancient Church of the EastFormed in the 1960s from the Assyrian Church of the East, over the adoption of the Gregorian calendar and changes to the fast16

Signature

Calendar
The Chaldean, Syro-Malabar and Assyrian Churches keep the Gregorian calendar; the Ancient Church of the East keeps the Julian.5
Bread
Leavened bread; the Assyrian Church's own history speaks of the leavened loaf.3
Languages
Syriac is the liturgical language, with Malayalam in use alongside it in the Syro-Malabar Church in India.5
Typical anaphora shape
Three anaphoras — of the Apostles (Addai and Mari), of Theodore, of Nestorius — with Addai and Mari appointed from Palm Sunday to the end of the year.4

The Shape of the Liturgy

Shape of the The Chaldean Tradition1. Opening dialogueDlg2. Preface / thanksgivingPref3. Pre-SanctusPreS4. SanctusSan5. Post-SanctusPostS6. Institution narrative (absent)Inst7. AnamnesisAnam8. OfferingOff9. Epiclesis (after anamnesis)Ep210. IntercessionsInt11. Commemorations / diptychsCom12. DoxologyDox
  1. 1. Opening dialogue
  2. 2. Preface / thanksgiving
  3. 3. Pre-Sanctus
  4. 4. Sanctus
  5. 5. Post-Sanctus
  6. 6. Institution narrative (absent)
  7. 7. Anamnesis
  8. 8. Offering
  9. 9. Epiclesis (after anamnesis)
  10. 10. Intercessions
  11. 11. Commemorations / diptychs
  12. 12. Doxology
Typical shape of the Chaldean anaphora9

Its institution words are not given in a coherent narrative and ad litteram, but 'in a dispersed euchological way', integrated in the prayers of thanksgiving, praise and intercession9.

  • Opening dialogue
  • Preface / thanksgiving
  • Pre-Sanctus
  • Sanctus
  • Post-Sanctus
  • Institution narrative
  • Anamnesis
  • Offering
  • Epiclesis (after anamnesis)
  • Intercessions
  • Commemorations / diptychs
  • Doxology

Each colour is one part of the eucharistic prayer, in the order the prayer says it. Compare every anaphora.

History

The tradition's roots lie in the Syriac-speaking Christianity of Mesopotamia and Persia. The Church of the East's own history holds its founding in the middle of the first century and recounts the missions that carried its worship to India and China3. In the Sasanian empire the bishop of Seleucia-Ctesiphon rose to head the Persian Church: the Church's account names Papa bar Gaggai, about 310, as the first "Catholicos of the East", and the title "Patriarch" was received at the synod of Seleucia-Ctesiphon in 4103. From this Mesopotamian centre the tradition's Qurbana took the shape it largely keeps today.

The Anaphora of the Apostles, Addai and Mari, is among the oldest eucharistic prayers in continuous use: its oldest known witness is the Mar Esha'ya hudra, and a seventh-century revision is ascribed to the catholicos Isho'yahb III17. The prayer moves from thanksgiving through the Sanctus to the commemoration of the passion and the epiclesis, but it never settles into a narrative of the Last Supper: the institution words stand, as Rome's study put it, "in a dispersed euchological way"9. The Assyrian synod of 1978 had allowed its ministers the option of reciting the institution words; the synod at Thrissur in January 2010 repealed that permission13.

In 1552–53 part of the Church of the East entered full communion with the Apostolic See — the line usually called "Chaldean"4. The name itself is older: Latin authorities had first used "Chaldean" at the Council of Florence in 144513. The new union's Shim'un line later drifted from Rome, while the older Eliya line of Alqosh drew toward it; by 1830 that line had become entirely Catholic, and the Chaldean patriarchate stood consolidated in union with Rome18.

In India the Thomas Christians kept their East Syriac worship under Persian bishops into the Portuguese age. The Synod of Diamper — Udayamperur — of 1599 broke that continuity, altering the received books: the names of Nestorius and Theodore were removed, their anaphoras ordered burned, unleavened bread was imposed and Latin practices introduced2. The twentieth century undid the imposition: a restoration committee was appointed in 1954, Pius XII approved the revised Qurbana in 1957, a Syriac Taksa appeared in 1960 with a Malayalam text in 1962, and the Raza Taksa was approved in 19852.

The twentieth century was harsher for the Church of the East at home. Its own account records tens of thousands of lives lost between 1918 and 1920, and another wave of atrocities in 1933 at the hands of the Iraqi monarchy18. The patriarchate moved westward in exile and finally to Erbil, affirmed as the patriarchal diocese by the 2021 synod; Mar Awa III was elected Catholicos-Patriarch on 8 September 202119,20. The Ancient Church of the East came into existence in 1968 in opposition to the adoption of the Gregorian calendar and changes to the fast; Mar Georges III Younan was installed as its patriarch at Baghdad on 9 June 20237,21.

Today the Chaldean Church prays a Qurbana reformed by its synod on 12 November 2005 and recognised by the Holy See on 18 February 200613. Its synod, meeting in Rome, elected Amel Shamon Nona as patriarch on 12 April 2026; he took the name Polis III and received ecclesiastical communion on 24 April 202610,22. The dialogue continues: the 2017 Common Statement on "Sacramental Life" carried the 1994 and 2001 agreements into a new phase on liturgy23.

Milestones

  1. mid-1st centuryThe Church of the East's own tradition holds its founding in the middle of the first century, with missions carrying its worship to Persia, India and China.3
  2. AD 410At a synod at Seleucia-Ctesiphon the head of the Persian Church received the title 'Patriarch', consolidating the catholicosate's authority.3
  3. 1552–53Part of the Church of the East entered full communion with the Apostolic See — the line usually called 'Chaldean'.4
  4. 1599The Synod of Diamper (Udayamperur) altered the received East Syriac books and discipline of the Thomas Christians of India.2
  5. 1830By 1830 the old Eliya (Alqosh) line had become entirely Catholic, consolidating the Chaldean patriarchate in union with Rome.18
  6. 11 November 1994John Paul II and Mar Dinkha IV signed the Common Christological Declaration between the Catholic Church and the Assyrian Church of the East.14
  7. 20 July 2001The Holy See's Guidelines recognised the Anaphora of Addai and Mari as valid and regulated eucharistic admission, in necessity, between the Chaldean and Assyrian faithful.9

Sources

  1. Magisterial / canonicalCode of Canons of the Eastern Churches, Vatican City: Libreria Editrice Vaticana, 1990, can. 28 §2. LinkVerified 2026-09-12 · URL repointed 18 Sep 2026 to the Latin text on vatican.va (part 1; cann. 656–657 are in part 2, codex-can-eccl-orient-2), because the caedm.ca English extract (616A) carries cc. 27–38 only; cann. 28, 40 §1, 656, 657 read there in the Latin, 18 Sep 2026. English translation: cann. 27–28 read in the caedm.ca PDF; cann. 671, 697, 707, 710, 713 read in the IntraText English edition; can. 881 §1 in IntraText, 2026-09-14
  2. Primary textThe Major Archiepiscopal Commissions for Liturgy and Catechesis of the Syro-Malabar Church, The Liturgical Catechesis of the Syro-Malabar Church, 2015, the Malayalam text of 1962; the 1599 synod; the restoration; the Synod of Udayamperur/Diamper (1599). LinkVerified 2026-09-20 · read in full (English): East Syriac relations with Persia; the Synod of Udayamperur/Diamper (1599) altered the received East Syriac books and discipline (Nestorius and Theodore removed, their anaphoras ordered burned, unleavened bread imposed, Communion in both kinds ended, Latin practices introduced); restoration committee appointed 1954 (Placid Podipara); Pius XII approved the Revised Order of the Qurbana 1957; Ordo Celebrationis Qudasae 1959, Supplementum Mysteriorum 1960, Syriac Taksa d'Qudasae 1960, a partial Malayalam text published and introduced 1962, a 1968 amended Taksa provisionally approved, the Raza Taksa approved 1985
  3. Primary textAssyrian Church of the East, Ancient History, the Persian Church; leavened loaf; the founding tradition; India and China; c. 310; the 410 synod; the apostolic founding tradition and the spread to India and China; the 410 synod at Seleucia-Ctesiphon. LinkVerified 2026-09-19 · the Church's own history page: the apostolic founding tradition, the Persian Church, the spread to India and China
  4. Magisterial / canonicalPontifical Council for Promoting Christian Unity, Explanatory note to the 2001 Guidelines on Addai and Mari and admission to the Eucharist, Rome, 2001, the three anaphoras and their seasons; sec. 1; the 1552 union; 'In 1552 … part of the Church of the East entered into full communion'.Verified 2026-09-19 · the explanatory note read in full and kept distinct from the Guidelines themselves: it treats the anaphora's shape and states the Holy Leaven is renewed by the local bishop, who distributes it to the parishes of his diocese
  5. ReferencePRO ORIENTE (Vienna), The Chaldean Catholic Church, Gregorian calendar; the see at Baghdad; Gregorian calendar; PROORIENTEAssyrian: Gregorian calendar; PROORIENTEAncient: Julian calendar; Syriac liturgical language; SMCCatechesis2015: Malayalam text introduced 1962. LinkVerified 2026-09-20 · read: 'approx. 650,000' believers; 24 bishops, 19 dioceses; East Syrian rite; Syriac liturgical language; Gregorian calendar; the see at Baghdad
  6. ReferencePRO ORIENTE (Vienna), Assyrian Church of the East, Gregorian calendar; Mar Awa III; the see at Erbil. LinkVerified 2026-09-20 · read: 'approx. 400,000' faithful; Mar Awa III (Royel), in office since 2021; 15 bishops, 12 dioceses; East Syrian rite; Syriac liturgical language; Gregorian calendar; the see at Erbil
  7. ReferencePRO ORIENTE (Vienna), The Old Apostolic Church of the East, Julian calendar; 1968. LinkVerified 2026-09-20 · read: 'approx. 70,000' faithful; 9 bishops, 8 dioceses; East Syrian rite; Syriac liturgical language; Julian calendar; the see at Baghdad; the Church came into existence in 1968 over the Gregorian calendar and the fasting rules. The page still names the patriarch elected in June 2022, who later abdicated; it is not used here for the present head
  8. Primary textLazarists of Urmia (ed.), Takhsa d-Quddasha: the Order of the Holy Qurbana, Urmia, 1890, the text of Addai and Mari.Verified 2026-09-19 · the 1890 Urmia printing read in Syriac: its text of Addai and Mari prints no institution narrative; the narrative exists in the examined copy only as a separately printed leaf of unknown printer and date bound in at that point
  9. Magisterial / canonicalPontifical Council for Promoting Christian Unity, Guidelines for admission to the Eucharist between the Chaldean Church and the Assyrian Church of the East, Rome, 2001, the 2001 decision; provisions 1–4; the institution words 'in a dispersed euchological way'; UrmiaTakhsa1890: the 1890 text prints no institution narrative; the third argument; the 2001 recognition and provisions 1–4. LinkVerified 2026-09-20 · the Guidelines read in full on the Council's own site: Rome, 20 July 2001; the institution words are 'not in a coherent narrative way and ad litteram, but rather in a dispersed euchological way, that is, integrated in successive prayers of thanksgiving, praise and intercession'; guidelines 1-4, the whole applying exclusively to Chaldean and Assyrian faithful
  10. Magisterial / canonicalHoly See Press Office, Elezione del Patriarca di Baghdad dei Caldei (Iraq), 2026, elected 12 April 2026; 12 April 2026. LinkVerified 2026-09-20 · the 13 April 2026 bulletin read: the synod of bishops of the Patriarchal Church of Baghdad of the Chaldeans, meeting in Rome, elected Amel Shamon Nona Patriarch on 12 April 2026, and he took the name Polis III; born at Alqosh 1 November 1967, ordained priest 11 January 1991, elected archbishop of Mosul 13 November 2009 (ordained 8 January 2010), named bishop of the eparchy of Saint Thomas the Apostle of Sydney 15 January 2015 with the personal title of archbishop
  11. Magisterial / canonicalHoly See Press Office, Election of the Major Archbishop of the Syro-Malabar Church (10 January 2024 bulletin), 2024, elected 9 January 2024.Verified 2026-09-19 · the 10 January 2024 bulletin: Raphael Thattil elected Major Archbishop of the Syro-Malabar Church by the synod on 9 January 2024 and confirmed by Pope Francis the same day
  12. Primary textDiocese of Palghat (Syro-Malabar Eparchy), The Syro Malabar Church, 4,923,490 in all. LinkVerified 2026-09-20 · the diocesan page's account of the Church's own statistics: 4,442,852 Syro-Malabarians within the 34 Syro-Malabar eparchies and 1 exarchy, about 480,638 living as migrants outside any eparchy, 4,923,490 in all ('nearly 5 million'); 62 bishops, 8,547 priests, 32,114 women religious, 1,214 major seminarians
  13. ScholarshipRoyel, Mar Awa, The Pearl of Great Price, 2014, on the nomenclature; 1978 and 2010; Florence, 1445; the 2005–2006 reform.Verified 2026-09-19 · Mar Awa Royel's study read: the 1978 Assyrian synod's option to recite the institution words and its repeal by the January 2010 Thrissur synod; the Chaldean reform, synodally approved 12 November 2005, recognition reported 18 February 2006, appointed beginning 6 January 2007; in the Chaldean books the narrative stands after the intercessions and before the epiclesis
  14. Magisterial / canonicalJohn Paul II and Mar Dinkha IV, Common Christological Declaration between the Catholic Church and the Assyrian Church of the East, Rome, 1994, 11 November 1994; signed at St Peter's, 11 November 1994. LinkVerified 2026-09-20 · read in full on vatican.va: signed at St Peter's, 11 November 1994; the common confession of the same faith in the mystery of the Incarnation; 'Mother of Christ our God and Saviour' and 'Theotokos' both legitimate and right; a Mixed Committee for theological dialogue established
  15. ReferenceCatholic World Report (CNA), Syro-Malabar Catholic Church leaders want a uniform liturgy. Why are they facing resistance?. LinkVerified 2026-09-20 · read in full: interviews Mar Joseph Srampickal (Eparchy of Great Britain) — the 1999 synodal compromise (Word facing the people, Anaphora facing the altar); John Paul II inaugurated the restored Holy Qurbana during his 1986 India visit; the Church raised to major archiepiscopal in 1992; Synod of August 2021 mandated the 1999 formula from Advent 2021; Ernakulam-Angamaly kept the status quo on a Vatican dispensation; diaspora eparchies in the U.S., Canada, the U.K., Australia and New Zealand
  16. ReferenceAssyrian International News Agency, Ancient Church of the East Appoints New Patriarch, 2023. LinkVerified 2026-09-20 · read: Mar Georges III Younan, born in Iraq and raised in the United States, elected Patriarch of the Ancient Church of the East and installed at Holy Mary Cathedral, Baghdad, on 9 June 2023; succeeds Thoma Darmo (1968-1969) and Addai II Giwargis (1972-2022)
  17. ScholarshipMacomber, William F., “The Oldest Known Text of the Anaphora of the Apostles Addai and Mari”, Orientalia Christiana Periodica, 1966, the oldest witness; the seventh-century revision.Verified 2026-09-19 · read: the seventh-century revision of Addai and Mari ascribed to Isho'yahb III (the 'II' on p. 348 is corrected on p. 349); the Mar Esha'ya Hudra is the oldest known witness of the anaphora
  18. Primary textAssyrian Church of the East, Modern History, 1830; 1918–20; 1933; 'By 1830, the old Mar Elia line of Alqosh had become entirely Roman Catholic'. LinkVerified 2026-09-19 · the Church's own history page: the 1552-53 union line, the patriarchal successions, the modern persecutions
  19. Primary textAssyrian Church of the East, Catholicos-Patriarch, the 2021 election. LinkVerified 2026-09-19 · the Church's own patriarch page: Mar Awa III, elected 8 September 2021 and consecrated 13 September 2021 at Ankawa
  20. Primary textAssyrian Church of the East, Decrees of the Holy Synod, 2021, Erbil affirmed. LinkVerified 2026-09-19 · the 2021 synod decrees: Erbil affirmed as the patriarchal diocese
  21. ReferenceTulloch, Joseph, “Mar Georges III Younan: New patriarch for the Ancient Church of the East”, Abouna (carrying the Vatican News report in full), 2023, 9 June 2023. LinkVerified 2026-09-20 · read: Mar Georges III Younan appointed Patriarch of the Ancient Church of the East at Holy Mary Cathedral, Baghdad, on Friday 9 June 2023; the Church split from the Assyrian Church of the East in the 1960s; Patriarch Louis Sako of the Chaldeans visited Mar Younan afterwards
  22. Magisterial / canonicalHoly See Press Office, Concessione dell'Ecclesiastica Communio al Patriarca di Baghdad dei Caldei, 2026, 24 April 2026. LinkVerified 2026-09-20 · the 28 April 2026 bulletin read: Pope Leo XIV, on 24 April 2026, granted the ecclesiastical communion requested by Polis III Nona, canonically elected Patriarch of Baghdad of the Chaldeans on 12 April 2026, under can. 76 section 2 CCEO
  23. Magisterial / canonicalJoint Committee for Theological Dialogue between the Catholic Church and the Assyrian Church of the East, Common Statement on 'Sacramental Life', Rome, 2017, 24 November 2017. LinkVerified 2026-09-20 · read in full: signed 24 November 2017 by Cardinal Kurt Koch and Metropolitan Mar Meelis Zaia; the Holy Leaven is not practised by the Chaldean or Syro-Malabar Church; the Leaven is renewed by the local parish priest; no co-celebration of the sacraments and rites by the two Churches' clergy (n. 28)
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