It is not known exactly when Christianity first took root in upper Mesopotamia, but a Christian presence had certainly been established there by the mid-2nd century. In the 3rd century, the area was conquered by the Persians. Although this was to be a multi-ethnic church, the Assyrian people traditionally played a central role in its ecclesial life. Its geographical location caused it to become known simply as “the Church of the East.”
Around the year 300, the bishops were first organized into an ecclesiastical structure under the leadership of a Catholicos, the bishop of the Persian royal capital at Seleucia-Ctesiphon. He later received the additional title of Patriarch.
In the 5th century, the Church of the East gravitated towards the radical Antiochene form of christology that had been articulated by Theodore of Mopsuestia and Nestorius, and fell out of communion with the church in the Roman Empire. This was due in part to the significant influx of Nestorian Christians into Persia that took place following the condemnation of Nestorian christology by the Council of Ephesus in 431, and the expulsion of Nestorians from the Roman Empire by Emperor Zeno (474-491). In addition, the Persian Christians needed to distance themselves from the official church of the Roman Empire, with which Persia was frequently at war. In this way they were able to maintain their Christian faith while avoiding suspicions that they were collaborating with the Roman enemy.
Synods in the 5th century also decreed that celibacy should be obligatory for no one in this church, including bishops. A number of bishops and even patriarchs were married until the early 6th century, when the decision was taken to ordain only celibate monks to the episcopate. Priests, however, have always been allowed to marry, even after ordination.
The Church of the East was always a minority in largely Zoroastrian Persia, but nevertheless it flourished for many centuries, with its rich scholarly activity centered on the famous school of Nisibis. The church expanded through missionary activity into areas as far away as India, Tibet, China, and Mongolia. This continued even after the Mesopotamian homeland was conquered by the Muslim Arabs in the 7th century. The Patriarchate was moved to the new city of Baghdad after it became the capital in 766. By 1318 there were some 30 metropolitan sees and 200 suffragan dioceses. But during the invasions of Tamerlane in the late 14th century, these Christians were almost annihilated. By the 16th century, they had been reduced to a small community of Assyrians in what is now eastern Turkey. The church was then further weakened by the formation of a Catholic counterpart known as the Chaldean Catholic Church.
During World War I, the Assyrians suffered massive deportations and massacres at the hands of the Turks who suspected them of supporting the British enemy. About one third of the Assyrian population perished. Most of the survivors fled south into Iraq, hoping to be protected by the British. But in 1933, after the end of the British mandate in Iraq, a clash between Assyrians and Iraqi troops ended in another massacre and a further scattering of the community. The Iraqi authorities then stripped Assyrian Patriarch Mar Simon XXIII of his citizenship and expelled him. He went into exile in San Francisco, California, USA.
In 1964 a dispute arose within the church, triggered by Mar Simon’s decision to adopt the Gregorian calendar. But the real issue was the person of Mar Simon and the centuries-old practice by which he was elected. By 1450, the office of Patriarch and some other episcopal sees had become hereditary within one family, usually being passed down from uncle to nephew. This often produced unqualified leaders of the church who at times were elected at a very young age: Mar Simon himself had been elected at age 12. The dissidents also held that a Patriarch was needed who could live with his community in Iraq.
Those opposed to Mar Simon were supported by Mar Thomas Darmo, the Assyrian Metropolitan of India. In 1968 he traveled from India to Baghdad and ordained three new bishops. They then met in synod and elected him Patriarch over against Mar Simon. Mar Thomas Darmo died in the following year, and was succeeded in 1970 by Mar Addai of Baghdad. His faction became known as “The Ancient Church of the East.”
In 1973 Mar Simon resigned as Patriarch and married. As no successor could be agreed upon, the Assyrian bishops in communion with him attempted to persuade him to resume his office despite his marriage. But in the midst of these negotiations, on November 6, 1975, Mar Simon was assassinated in San Jose, California. The bishop of Tehran, Iran, was elected Patriarch in 1976 and adopted the name Mar Dinkha IV. He took up residence in the United States.
Mar Dinkha made it clear that with his election, the patriarchal dynasty had ended. This removed the major reason for the schism between the two groups. Although the rift has not yet been healed, recent meetings between bishops of the two sides have made progress towards resolving the dispute.
Meeting in Australia in July 1994, the Assyrian Holy Synod reached a number of important decisions concerning the life of this church. The bishops established a Commission on Interchurch Relations and Education Development to prepare for theological dialogues with other churches and develop programming in religious education. The Synod also officially sanctioned the residence of the Patriarch in Morton Grove, Illinois, USA.
A milestone in relations with the Roman Catholic Church was reached on November 11, 1994, when Mar Dinkha IV and Pope John Paul II signed a Common Christological Declaration in the Vatican. The statement affirms that Catholics and Assyrians are “united today in the confession of the same faith in the Son of God…” and envisages broad pastoral cooperation between the two churches, especially in the areas of catechesis and the formation of future priests. The Pope and Patriarch also established a mixed committee for theological dialogue and charged it with overcoming the obstacles that still prevent full communion. It began meeting annually in 1995, and in 2017 it released an important Common Statement on “Sacramental Life.”
This international theological dialogue between the Assyrians and the Catholic Church as a whole has been accompanied by an improvement in relations between the Assyrian Church of the East and its Catholic counterpart, the Chaldean Catholic Church. In November 1996 Mar Dinkha IV and Chaldean Patriarch Raphael I Bidawid met in Southfield, Michigan, and signed a Joint Patriarchal Statement that committed their two churches to working towards reintegration and pledged cooperation on pastoral questions such as the drafting of a common catechism, the setting up of a common seminary in the Chicago-Detroit area, the preservation of the Aramaic language, and other common pastoral programs between parishes and dioceses around the world.
On August 15, 1997, the two Patriarchs met again, in Roselle, Illinois, and ratified a “Joint Synodal Decree for Promoting Unity,” that had been signed by the members of both Holy Synods. It restated the areas of pastoral cooperation envisaged in the Joint Patriarchal Statement, recognized that Assyrians and Chaldeans should come to accept each other’s diverse practices as legitimate, formally implemented the establishment of an Assyrian-Chaldean “Joint Commission for Unity,” and declared that each side recognized the apostolic succession, sacraments and Christian witness of the other. The text also spelled out the central concerns of both sides in the dialogue. While both churches wanted to preserve the Aramaic language and culture, the Assyrians were intent on retaining their freedom and self-governance, and the Chaldeans affirmed the necessity of maintaining full communion with Rome.
In mid-1997 it was announced that the Assyrian Church of the East and the Syrian Orthodox Church had agreed to establish a bilateral theological dialogue. As a gesture to foster better relations with the Oriental Orthodox churches, the Assyrian Holy Synod decided in 1997 to remove from the liturgy all anathemata directed against others.
Although the Assyrians accept only the first two ecumenical councils, recent ecumenical discussions held under the auspices of the Pro Oriente foundation have concluded that in substance the faith of the Assyrian Church is consistent with the christological teaching of the Council of Chalcedon (451). Officially the church adheres to extreme Antiochian christological terminology, according to which in Christ there are two natures and two qnoma (a Syriac term with no Greek equivalent that refers to an individual but never personalized concrete nature) in one person. The synod of bishops has requested that their church not be called nestorian, since this term has been used in the past to insult them. The Assyrians are not in full communion with any other church.
The East Syrian rite of the Assyrian Church appears to have been an independent development from the ancient Syriac liturgy of Edessa. It may also preserve elements of an ancient Persian rite that has been lost. Services are still held predominantly in Syriac.
Mar Dinkha IV passed away on March 26, 2015. The election of a successor was originally scheduled to take place in June, but was delayed until September pending the outcome of a dialogue with the Ancient Church of the East regarding possible reunification. Unfortunately that dialogue was not successful, and the bishops of the Assyrian Church of the East elected Bishop Gewargis Sliwa as the new patriarch on September 18, 2015. One of his first acts in office was to announce that the headquarters of the church would be moved from Chicago (where Mar Dinkha IV had resided) to the city of Erbil in the Kurdistan region of Iraq.
The Assyrian Church has a scattered presence outside its Iraqi homeland. Mar Paulus Benjamin is the Bishop of the Diocese of the Eastern USA (7201 North Ashland Blvd., Chicago, Illinois 60659). Mar Aprim Khamis is Bishop of the Western United States (18221 N. 59th Drive, Glendale, Arizona 85308), and Mar Awa Royel is Bishop of California and Secretary of the Holy Synod (1457 Mable Avenue, Modesto, California 95355). Altogether there are about 20 parishes in the country. Mar Emmanuel Joseph is Bishop of Canada, where there are four parishes and a mission (161 Skyway Avenue, Toronto, Ontario). The Archdiocese of Australia, New Zealand and Lebanon, with six worshiping communities in Australia and two in New Zealand, is headed by Mar Meelis Zaia (25 Edinburgh Circuit, Cecil Hills, NSW 2171, Australia). There is also one Assyrian parish in London (St Mary’s Church, Westminster Road, Hanwell, W7 3TU) under the jurisdiction of Mar Awraham Youkhanis, Bishop of Western Europe.
Location: Iraq, Iran, Syria, Lebanon, North America, Australia, India
Head: Mar Gewargis III (born 1941, elected 2015)
Title: Catholicos-Patriarch of the Church of the East
Residence: Erbil, Iraq