Ancient Church of the East
Ancient Church of the East belongs to the Assyrian Church of the East family of churches.
Governance: episcopal.
The 1968 branch of the Church of the East (calendar and patriarchal disputes), with parishes in the Assyrian diaspora including the US; reconciliation talks with the Assyrian Church of the East have continued for years.
Congregation count not yet source-verified against RCMS 2020; NULL rather than estimated.
The 1968 branch of the Church of the East — separated over the calendar and the old hereditary patriarchate, seated in Baghdad, and in long-running reconciliation talks with its sister church.
Heritage
In 1968, amid disputes over the adoption of the Gregorian calendar and the abolition of hereditary succession to the patriarchate, a group of Church of the East bishops consecrated Mar Thoma Darmo as a rival catholicos-patriarch, seated in Baghdad. The Ancient Church of the East has since kept the Julian calendar and the older usages, with parishes across the Assyrian diaspora, including the United States. Reconciliation talks with the Assyrian Church of the East have continued for years and have brought the two churches closer than at any time since the split.
Theological family
Identical in faith and rite to the Assyrian Church of the East — the East Syriac tradition, the Liturgy of Addai and Mari. The division is calendrical and administrative, not doctrinal.
Who decides what
Its own catholicos-patriarch in Baghdad with a small synod of bishops over diaspora dioceses; parishes led by priests, many married.
What a first-time visitor would find
The East Syriac liturgy on the Julian calendar, in Syriac and Assyrian neo-Aramaic with English — long, chanted, and ancient; the great feasts fall roughly two weeks after their Gregorian dates.
What it has always cared about
Fidelity to received usages — the old calendar above all; Assyrian language and identity held together in diaspora.
Its gift to the wider church
Together with its sister church it keeps the East Syriac inheritance alive, and their patient reconciliation talks model how a family quarrel inside an ancient church can be walked back rather than hardened.
Commonly confused with
With the Assyrian Church of the East, from which it separated — the two share everything but calendar and hierarchy; and with the Chaldean Catholic Church, the branch of the same heritage in communion with Rome.
Range of views inside it
A small communion; parishes differ mainly in language mix and diaspora generation.
A note from the mapmakers: Our source (RCMS 2020) publishes no US congregation count for this church, so we print none. Nothing here may be asserted of a specific parish, including where its loyalties sit in the reconciliation process. Sentences drawn from this record hedge as "Ancient Church of the East parishes typically…" and yield to the parish's own materials.
Sources: The Church of the East: A Concise History (Wilhelm Baum and Dietmar W. Winkler, Routledge) · Encyclopedia of American Religions (J. Gordon Melton, Gale)
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