Ancient Church of the East

The Ancient Church of the East is an Eastern Christian denomination. It branched from the Assyrian Church of the East in 1964, under the leadership of Mar Toma Darmo (d. 1969). It is one of three Assyrian Churches that claim continuity with the historical Church of the East (the ancient Patriarchal Province of Seleucia-Ctesiphon), the others being the Assyrian Church of the East and the Chaldean Catholic Church. Since 1969, the see of the Ancient Church of the East is headquartered in Baghdad.

History
The Ancient Church of the East is yet another name historically used for the Church of the East. This name became officially used when a schism happened in 1964, due to a decision made by the Patriarch Mar Shimun XXIII Eshai, to switch over from the traditional Julian Calendar which the church has been following since its establishment before the mid first century CE to the Gregorian Calendar. Part of the Church of the East, then led by the Patriarch Mar Shimun XXIII Eshai, continued with the Patriarch's decision. This became the reason for the schism.

The Ancient Church of the East in 1968 consecrated their own Patriarch, Mar Toma Darmo, who strongly opposed to the system of hereditary succession of the position of patriarch of the Church of the East, as well as its adoption of the Gregorian calendar "and other modernizing measures". Mar Darmo was also joined by "various other groups opposed to Mar Shimun."

In 2011, Mar Mari Emmanuel was ordained a bishop in the Church in Australia, before he was excommunicated in July 2014 over "theological differences". Mar Yacob III Daniel was elected as new patriarch in June 2022. In the month of August, patriarch-elect Mar Yacob III Daniel abdicated, and on 12 November 2022 the Holy Synod elected Mar Gewargis Younan to take his place. The consecration of the Patriarch-elect was scheduled to take place in Baghdad in June 2023, and on 9 June, Patriarch Elect Mar Gewargis III Younan was consecrated as the 110th Patriarch of The Ancient Church of The East.

Holy Synod
The Holy Synod is as follow:
 * Mar Gewargis III Younan, Catholicos-Patriarch (seat in Baghdad, Iraq)
 * Mar Yacob Daniel, Metropolitan of the Archdiocese of Baghdad and Basra (seat in Baghdad and Basra)
 * Mar Zaia Khoshaba, Metropolitan of the Archdiocese of Canada and the United States (seat in Toronto, Canada)
 * Mar Toma Aramia, Metropolitan who resides in Canada (seat in Toronto, Canada)
 * Mar Shimun Daniel Alkhoury, Bishop of Iraq and the Middle East.

Since 1968

 * Thoma Darmo (1968–1969)
 * Addai II Giwargis (1972–2022)
 * Yacob III Daniel (2022-2022)
 * Gewargis III Younan (9 June 2023 – present)

Relationship with the Assyrian Church of the East
Under the tenure of Addai II, the Ancient Church of the East has made several gestures towards reunification with the Assyrian Church of the East. The most prominent of these is undoubtedly the declaration made in June 2010 stating that the Ancient Church of the East would now celebrate Christmas in accordance with the Gregorian calendar. Previously, the church used the traditional Julian date for the Christmas Day (December 25 of the Julian calendar currently corresponds to January 7 of the Gregorian Calendar), as the Church of the East had throughout its history. The decision was to be implemented later that year, on December 25, 2010.

Dialogue for reunification
Following the death (March 2015) of Dinkha IV, Catholicos-Patriarch of the Assyrian Church of the East, dialogue of unification continued between the churches.

On May 22, 2015, a meeting involving prelates of both Holy Councils took place in a suburb of Chicago, Illinois, in the library of St. Andrew's Assyrian Church of the East. Present were Yacoub Daniel, Zaia Khoshaba, and Gewargis Younan representing the Ancient Church of the East, and Gewargis Sliwa, Awa Royel, and Iskhaq Yousif representing the Assyrian Church of the East. Archdeacon William Toma served as the meeting's common secretary. Yacoub Daniel flew in from Australia for the meeting, and Zaia traveled from Canada.

On June 1, 2015, the Holy Synod of the Assyrian Church of the East met in Erbil, Iraq, to discuss the future of the church. The date had previously been arranged for the election of the new Catholicos-Patriarch. Awa Royel issued a statement on the same day, notifying the public that a response to the Ancient Church of the East's recommendations for reunification had been delivered to their prelates. The letter requested a prompt response to the terms, and the election of the new Patriarch was suspended until the following week, on June 8, 2015.

On June 5, 2015, Aprem Mooken issued a formal statement announcing that the election of the next Catholicos-Patriarch of the Assyrian Church of the East was suspended until September (2015), pending the unification of the churches.

It turned out that unification was not achievable. On 18 September, Assyrian Church of the East elected Gewargis III as the new head of the Church, and he was consecrated and enthroned as Catholicos-Patriarch on 27 September 2015.

In spite of the fact that unification was not achieved, leaders of both Churches have continued to promote various forms of mutual cooperation.

After the death of Mar Addai II, reunification failed in May 2022 and the election of a new patriarch was therefore launched.