History of the Chaldean Church

by Anthony O’Mahony

Chaldean Catholic Church

The Chaldean Catholic Church traces its origins back to ancient East Syriac Christianity that flourished beyond the boundaries of the Roman Empire. It has been called the “Church of the East,” or—especially for the period of late antiquity—the “Persian Church.” The appellations “Chaldeans,” “Assyrians,” “Aramaeans” and “Mesopotamians” are names which came into use relatively late. They refer to a remote past and evoke ancient civilizations, although they describe the same people from different perspectives.

The Aramaic dialect, Syriac (sureth), which is still spoken nowadays by most of the faithful, was the language of trade and commerce throughout the eastern lands.

The term “Chaldean” was used to designate East Syriac Christians in some manuscripts and upon the tombs of patriarchs, but officially it was first used in the fifteenth century to designate those East Syriac Christians in Cyprus who came into union with the Roman Catholic Church during the council of Florence–Rome (1445). In the eighteenth century it was occasionally used by the East Syriac patriarchs established in Amid (Diyarbakir, Turkey) who came into communion with the Catholic Church. While in earlier centuries simply the term “Catholic” was used, the term “Chaldean” was preferred and became official after 1818. At that time, two of the three jurisdictions of the Church of the East—the Amid and Mosul patriarchates—reunited and since then have been in communion with the Roman Catholic Church.


  1. East Syriac Christianity from late antiquity to the Arab conquest

The sources for the origins of the Church of the East—i.e., east of the Tigris, as well as in Adiabene and Khuzestan—are scanty. It is thought that Christianity spread into the Persian Empire from the Osroene and its capital Edessa (Urfa) and from the regions surrounding Nisibis (Nusaybin), Palmyra or Hatra as early as the beginning of the second century. The first Christian congregations emerged from the Jewish communities, which had been present in Mesopotamia at least since the Ninevite and Babylonian exile, and among other Aramaic speaking Semites of the Parthian empire, where the attitude towards Christians was tolerant or at least indifferent.

This is also reflected in the ancient yet historically conflicting missionary traditions of the Church of the East. According to the best-known and most widely disseminated version, the apostle Thomas was the first to evangelize those regions during his travels through Mesopotamia, Persia and Media to India. He sent some of his disciples to Mesopotamia. The name of Mar Addai is connected with the region of Edessa, while Mar Mari is considered as having established the Church in Seleucia and Ctesiphon, the royal cities of the Persian Empire.

Another set of traditions refers to the first converts to Christianity coming from among the Jews. According to tradition, the family of Jesus was among those who reached Mesopotamia after the destruction of the temple of Jerusalem in the year 70.

Beginning with the early third century, Christianity can be explored in both literary and archeological sources. Additional factors for the development of Christianity were the expanding movement of refugees and the wartime deportations occurring because of the perpetual conflict between the Persian and the Roman Empires. When King (Shah) Shapur I (240–272) and his army advanced far into Roman territory and captured Antioch, many Christians from that area—Syria, Cappadocia, Cilicia—were deported to Persian provinces, where they helped to spread Christianity.

In the times of Shapur I, the Church of the East already had an episcopal structure. Under Shapur II (309–379) the Christians in the Persian Empire became the object of horrendous persecutions.

Sasanian King Yazdegerd I (399–421) sought to ease political tensions with the Romans and began to integrate Christians into imperial politics. Thus began a period of diplomatic exchanges in which the Christian hierarchy of Persia played an essential role as heads of Persian diplomatic missions because of their fidelity and their knowledge of languages. They were mainly clerics from the border cities. Likewise, the Roman emperor was represented by Christian delegates at the Persian courts. The influence of the Roman envoy Marutha, the Aramaic bishop of the border city Maypherkat, led to the first East Syriac Synod, held under Isaac, the “Grand Metropolitan” of Seleucia-Ctesiphon (410). This synod of forty bishops provided an essential contribution to the organization of the Church of the East, under the primacy of the bishop of Seleucia-Ctesiphon. The conformity of the Persian Church (which had spread now as far as Merv) with the Nicene faith was firmly established.

The unity of the Church of the East under its own single head was stressed also in the following synods of 420 and 424. The synod of Markabta (424), under Catholicos Dadisho, particularly emphasized that the bishop of Seleucia-Ctesiphon, subsequently called “catholicos-patriarch,” was the head of the Church and the successor of Peter, the head of the apostles. Thus an appeal to “Western” patriarchs in the Roman Empire was seen as neither necessary nor allowed. With these three synods, the Church of the East presented itself as a strongly structured and organized autonomous church. However, contacts with the Churches of the Roman Empire were in no way broken off. “Western” theological developments entered the Persian Church particularly through the School of Edessa. After the Romans ceded Nisibis to the Persians in 363, Ephrem, the famous deacon-poet of Nisibis, immigrated to Edessa where he continued to teach. After his death (373), the “School of the Persians” in Edessa came under the influence of the Antiochene exegetes, especially Theodore of Mopsuestia († 428), whose works were there translated into Syriac.

During the first period of the Christological disputes in the fifth century, the school kept firm to its Antiochene tradition, but afterwards Mar Narsai († 503), the head of the school, had to flee across the border to Nisibis because Emperor Zeno expelled the teachers and closed down the School of Edessa (489). In Nisibis, Barsauma, the bishop of the city, received Narsai and supported him to create the new School of Nisibis, which became the cultural and theological centre of the Church of the East.

The Synods of Beth Lapat (484) and Seleucia-Ctesiphon (486) have been seen as synods where the Church of the East officially adopted “Nestorianism”. Indeed, the creeds of these synods can be identified as a strict and orthodox expression of the Antiochene Christology. Moreover, Nestorius was never even mentioned in any of the synods that took place in the fifth and sixth centuries. The Church of the East continued to consider itself as an integral part of the universal Church, but political circumstances made a participation in the great councils (known as “ecumenical councils”) impossible. This Church outside the Roman Empire remained isolated throughout its history.

In the fifth century East Syriac Christianity had spread across Mesopotamia and expanded into the Arabian Peninsula and among nomadic and semi-nomadic Arab and Turkish tribes in central Asia. The Church was strengthened under the outstanding Catholicos Aba I (540–552), who reorganized the Church after renewed persecutions during the Persian-Roman War (540–545).

The sixth century saw a reform and revival of monasticism with Abraham of Kashkar († 588) as its central figure, with the foundation of hundreds of monasteries all over the country. Meanwhile a bitter dispute broke out in the School of Nisibis, where Henana of Adiabene, its director and an exceptional teacher, opposed the theological authority of Theodore of Mopsuestia. As the debate escalated in the school, approximately three hundred members left. As a consequence, the synod of Catholicos Sabrisho I (596) anathematized all those who rejected the interpretations, commentaries and teachings of Theodore, and the first synod of the seventh century (605) proclaimed him as the official authority and the irrefutable standard of the East Syriac orthodoxy.

Another problem arose with the West Syriac Miaphysites (non-Chalcedonians) who were gaining strength in the Persian Empire, with their metropolitan (maphrian) of Tikrit. This induced the Church of the East to define its Christology more precisely. In 612, King Khosrow II (591–628) arranged for a religious debate between East and West Syrians. At that time the shah forbade the choice of a successor for the See of Seleucia-Ctesiphon. During this period of vacancy (608–628), Babai the Great (551–628) and Archdeacon Aba of Seleucia led the East Syriac Church. Babai became the most outstanding theological figure of the East Syriac Church at the turn of the seventh century. His Christology clarified Theodore’s Christology, and his terminology was adopted by the Church in the theological debate of 612.

By 618-619 Khosrow II had extended the Persian Empire to the West and conquered Palestine and Egypt. The subsequent military successes of Byzantine Emperor Heraclius (610–641) finally resulted in a revolt against Khosrow II, who was murdered in a plot. With his death the vacancy of the See of Seleucia-Ctesiphon also came to an end. Queen Boran wanted a definitive peace treaty, and in 630 she sent an official delegation to Emperor Heraclius with this purpose. The diplomatic mission, led by Catholicos Isho’yahb II of Gdala, was crowned with political success and brought the region a few more years of temporary peace. However, a new power was already advancing from the south.

When the Arabs captured Seleucia-Ctesiphon in 637, Shah Yazdegerd III fled to the area around Merv. In 651 the Sasanian Empire vanished from history. Catholicos Isho’yahb moved his see to Karka d-Beth Slokh (Kirkuk). He died in 646, being the last catholicos under the Sasanians and the first of the Muslim era.



  1. Arab rule and the work translating Greek philosophical and scientific texts

 At the time of the Arab conquest, about one half of the population of what now constitutes Iraq and a great part of Iran were Christians. According to the stele of Si-ngan-fu (dated 781), found near the capital of the Tang Dynasty, a group of missionaries, guided by the monk Alopen, had reached China in 653. Additional metropolitanates were subsequently founded by Isho’yahb II at Hulwan (Iran), Herat (Afghanistan), Samarqand (Uzbekistan) and in China and India. In the conquered lands—the dar al-Islam—the Arabic language became established fairly quickly. Umayyad Caliph Al-Walid I (705–715) decreed it to be the official language of public administration. The new socio-economical environment made it necessary for Christians to use the language of the conqueror. Syriac nevertheless remained a literary and liturgical language.

The “People of the Book” (Jews, Christians, Zoroastrians) were treated as religious minorities under the protection of Islam (tolerated = dhimmi), believers in God despite their refusal to accept the prophethood of Muhammad. Adult male Christians were thus not required to convert (although that option was always open to them), but instead had to pay a poll tax (jizya) as price for this protection. Moreover, certain conditions were eventually imposed on the Christians, such as wearing a distinctive dress or girdle identifying them as such. In the eighth century (the second century of Islam’s existence) the laws became more stringent.

At the beginning of the Umayyad period the great Catholicos Isho’yahb III of Adiabene (650–658) led the East Syriac Church. He strengthened the primacy of his office and is especially known for his liturgical reform. He selected three anaphoras—those which bear the names of Addai and Mari, Theodore, and Nestorius—and at the same time banned all the others used previously. Together with the monk Henanisho, he is also responsible for the final redaction of the breviary known as the Prayer of the Hours (Hudra).

After the Abbasid revolution in 762, the caliphate was shifted from Damascus to Baghdad, the new capital and centre of the Islamic world. At the court of the Abbasid caliphs (750–1258) one of the most spectacular and momentous movements in the history of thought took place. Almost all secular Greek books on philosophy, sciences and medicine that were available throughout the former Eastern Roman and Persian Empires were translated, first into Syriac and then into Arabic. East Syriac Christians played a fundamental role in this translation movement, made indispensible for their knowledge of Syriac, Greek and Arabic. Through them the intellectual heritage of antiquity was transmitted to blossoming Arab scholarship and thereby provided the basis for the construction of the philosophical foundations of Islam. This process is of paramount cultural and historical significance also for the West, where works translated from Syriac or Arabic into Latin entered Europe through Spain and Sicily, even before the Greek originals were known.

Among the translators was the eminent Catholicos Timothy I (780—832), who supposedly also had a religious discussion with Caliph Al-Mahdi. Timothy was allowed to transfer the see of the catholicos to Baghdad, an honour granted to the East Syriac Church alone. His extensive collection of letters demonstrates that he was a born administrator and a staunch advocate of his Church.

Translations were produced not only by East Syriac clerics but also by lay persons who were skilled in medicine and philosophy. Among them the famous Bokhtisho family stands out. This was a Christian physician dynasty from the school of medicine in Gondeshapur, whose members served several caliphs. The best-known translator is Hunayn ibn Ishaq († 873), an East Syriac Christian Arab from Al-Hirah who translated medical texts (Galen), mathematical works (arithmetic, geometry, astronomy), and philosophical texts (in particular Aristotle). These authors were theologians at the same time (mutaklalimūn) and the term “theology” was translated into Arabic as Ilm al-Kalām, which means the science of speaking about God.

Although the politics of the Abbasid caliphs caused massive conversions of Christians to Islam, the Church of the East could expand within the Muslim empire towards the West. Among others we find bishoprics in Damascus, Jerusalem, Alexandria, Cyprus and along the Persian Gulf, especially in Qatar (Beth Qatraya), where we find eminent authors like Isaac of Nineveh, Gabriel and Job. Even more significant was the well-organized missionary enterprise towards the East. Monks sent by Timothy I travelled along the “silk road,” spreading the Gospel according to their Aramaic culture and liturgy but clothing their tradition in the cultural expressions of the peoples of Persia, Azerbaijan, Afghanistan, Turkistan, Mongolia, China, Tibet and India.


  1. The pinnacle (thirteenth and fourteenth centuries) and the first encounters with Latin Christianity

The first period of missionary efforts of the Church of the East came to an end in the middle of the ninth century, when the Chinese emperor of that time opposed the spread of foreign religions. At about the same time Christianity in central Asia, especially in Tibet, declined on account of strong Buddhist influence. In a new missionary period East Syrians succeeded in bringing Christianity to the Turco-Mongol peoples. In the eleventh century members of the Kerait tribe south of Lake Baikal were converted. When Genghis Khan established his power in this area in the thirteenth century, Christianity had already spread among other Mongolian tribes: Naiman, Uighur, Tangut and Ongut. When the Mongols conquered China, Christianity came back, this time not as a foreign religion but as part of the new ruling class of the empire.

The further conquest of the Mongols in the West strengthened central Asian Christianity. When the Mongols captured Baghdad in 1258, missions were flourishing along the “silk road” from the Oxus (Amu Darya) River to the Yellow Sea. The thirteenth and fourteenth centuries were the heyday of the Church of the East. Abdisho of Nisibis († 1318) listed about twenty metropolitan sees with 200 bishoprics.

The strong Christian presence in the Mongol army contributed to the birth in the West of the legend of the Christian king “Prester John,” which responded to desires of the hard-pressed Crusaders. At that time the first contacts with Latin Christianity appear. Franciscans and Dominicans reached the lands of the Mongols. Best known among them are William of Rubruck († 1270), Riccoldo da Monte di Croce († 1320) and Giovanni da Montecorvino († 1328). In 1340 other contacts were geographically closer: a group of East Syriac Christians in Cyprus placed themselves under the Catholic hierarchy. They were called “Chaldeans.” This union was successfully renewed in 1445, when the whole East Syriac community in Cyprus with its bishop Timothy of Tarsus established union with the Catholic Church during the reign of Pope Eugene IV (1431–1447) at the Council of Ferrara-Florence (1438–1445). Timothy received the title Archiepiscopus Chaldaeorum, qui in Cypro sunt. However, little by little the Chaldeans of Cyprus dissolved into local Maronite and Latin communities, and disappeared entirely after 1489.

Christian Mongol diplomats also reached the West. The most famous is the Uighur monk Bar Sauma, who had been the vicar general (saoura gawanaya) of the great Catholicos Yahballaha III (1291–1317). Bar Sauma was sent by the Mongolian II-Khan Arghun to Byzantine Emperor Andronicus II, King Philip IV of France, King Edward I of England and Pope Nicholas IV (1288–1292). According to his account, Bar Sauma celebrated the East Syriac Liturgy in Saint John Lateran, and finally received the Eucharist from the hand of the pope. It was through Bar Sauma’s journey that the Roman Curia became acquainted with the only vaguely known Church of the East.

Under Yahballaha III, the Church of the East had its largest extension from Jerusalem to China and India, with its centre in Baghdad, where the patriarch was allowed to occupy one of the former palaces of the Abbasids. However, when Arghun’s son Ghazan became Il-Khan, he officially professed Islam, with the result that the formerly-favoured Christians were attacked by the Muslims, churches were destroyed or turned into mosques and the patriarch’s residence was pillaged. The rapid decline of the most important missionary Church of the Middle Ages set in. Yahballaha’s successor Timothy II (1318–1331) held the last East Syriac synod whose acts have survived. No other synod is known prior to the nineteenth century.

In the last decades of the fourteenth century the cruel campaigns of the armies of Timur Lank (Tamerlane, 1336–1405) nearly wiped out the East Syriac Church in the Middle East. The communities beyond the Oxus then became isolated from the mother Church and disappeared after 1368, when the Mongol rule in China broke down.



  1. The foundation of the Sulaqa patriarchal line

 In the fifteenth century only a handful of churches in northern Mesopotamia had survived: in the plain of Mosul, around Urmiah, and in villages in the remote mountains of Hakkari in Kurdistan. Towards 1450, Catholicos-Patriarch Shimun IV Basidi († 1497) reserved the patriarchal office for members of his own family. The tradition of hereditary patriarchal succession led to one family dominating the church. This caused schism especially when untrained minors were being elected to the patriarchal throne. In 1539 Catholicos-Patriarch Shimun VII Bar Mama (1538–1558) was obliged to consecrate a twelve-year-old nephew as metropolitan because not enough suitable family members were available to fill the vacant positions in the dioceses. Some years later he consecrated a second nephew, aged fifteen.

In 1552 the catholicos-patriarch had become so unpopular that numerous opponents, especially from the Amid and Seert regions, met in an anti-synod at Mosul. They elected as patriarch Yohannan Sulaqa, hegumen of the Rabban Hormizd Monastery. The local dignitaries and clerics under the influence of Western missionaries sent Sulaqa with a delegation to Rome, to explain the situation and ask to be consecrated as bishop and confirmed as patriarch. His profession of faith was approved on 20 February 1553. Believing that Shemun Bar Mama had died, Pope Julius III confirmed Sulaqa as “Patriarch of Mosul” on 28 April 1553 by the bull Divina disponente clementia. When Patriarch Yohannan Sulaqa returned to Mesopotamia, he established himself in Amid (Diyarbakir) and strengthened his position. He ordained two metropolitans and three bishops. However, Catholicos-Patriarch Shimun Bar Mama won over the pasha (governor) of Amadiya, who summoned Sulaqa, imprisoned and tortured him for four months, and finally put him to death in January 1555. The Chaldean Church regards him as a martyr of the union with Rome.

The five bishops consecrated by Sulaqa elected as his successor Abdisho IV Maron (1555–1570). He travelled to Rome and obtained recognition from Pope Pius IV in 1562. Abdisho resided in a monastery near Seert, where he remained until his death. The succeeding patriarchs resided for security and pastoral reasons in Seert, Salmas, Khosrowa and Urmiah. They remained in communion with Rome until the seventeenth century, but none of them travelled to Rome personally to seek papal confirmation. Some of them never obtained official recognition, while others sent a profession of faith and were confirmed by Rome. The latter happened to Patriarch Shimun IX Dinkha (1580–1600) whose letter of confirmation (1581) was brought to Aleppo by the papal envoy Leonardo Abela and delivered to the patriarch in 1585.

When Shimun XIII Dinkha (1662–1700) definitively moved his see to Qudshanis in the remote mountains of Hakkari, this patriarchal line gradually returned to the traditional doctrine and worship. The patriarchate remained relatively isolated, and Rome lost contact with Qudshanis. It is unclear when the patriarchate became hereditary again, but it only ended in 1974. The present Assyrian Church of the East descends from this line and is the continuation of the Sulaqa line and the Qudshanis patriarchate.



  1. Three different patriarchal successions

When Shimun VII Bar Mama died in 1558, he was succeeded by his nephew Eliya VI Bar Giwargis (1559–1591). Although he and his successors resided in the Rabban Hormizd Monastery near Mosul, their strength made it impossible for the Sulaqa line to remain in Amid. His successor Eliya VII (1591–1617), possibly influenced by numerous East Syriac pilgrims who had converted to Catholicism in Jerusalem, sent emissaries to Rome in 1606/1607 and 1611. Under the influence of the Franciscan Thomas Obicini of Novara, Eliya VII held a synod (1616) that affirmed the Catholic Christological faith, but it did not result in a union. At the same time Rome also received a profession of faith from Shimun X of the Sulaqa line. Although the Franciscans tried to negotiate between the two East Syriac successions and to reach a Church union with Rome, formal links between the Vatican and the Mosul patriarchate in Rabban Hormizd were broken during the reign of Eliya VIII Shemun (1617–1660). Thus both patriarchates—Qudshanis and Mosul (Rabban Hormizd)—were not in communion with Rome in the second half of the seventeenth century.

In 1667, Capuchin missionary Jean-Baptist de St. Aignan worked among the East Syrians in Amid, and in 1672 convinced their metropolitan Joseph to become Catholic. In 1677, he gained recognition from the civil authorities as an independent bishop with jurisdiction over Amid and Mardin. Rome confirmed him in 1681 as Joseph I, “Patriarch of the Chaldean nation deprived of its patriarch.” Thus a third patriarchal line had been established in Amid. His successor Joseph II Sliba Marouf did much for the propagation of Catholicism. He translated many books from Italian into Syriac and even into Arabic in order to educate his flock.

The successors in the patriarchal line of Amid had significant success in spreading the Catholic faith within the boundaries of their jurisdiction as well as in the territories of the Mosul patriarchate. In the following decades, this led to severe conflicts between these two patriarchates, involving even the civil authorities.

In 1804 Augustine Hindi became bishop of Amid and apostolic administrator. He was not given the title of patriarch because at that time Rome saw a possibility of uniting the Amid and Mosul patriarchates. Although never fully recognized by the pope, Hindi’s service was rewarded in 1818 with the pallium, which he interpreted as a confirmation of his patriarchal status. For the rest of his life he used the title Joseph V. With his death in 1828 expired the patriarchate of Amid, which had existed in communion with Rome for 146 years. There finally remained only one officially recognized Catholic patriarch opposed to the Assyrian line of succession. The see was changing from place to place for security reasons and according to the presence of Catholic faithful.

  1. Yohannan Hormizd, the Chaldean patriarchal succession and communion with the Catholic Church

Although the Mosul patriarchate had lost its influence in the Amid and Mardin region, as well as in the Hakkari, it retained the influential Rabban Hormizd Monastery. Furthermore, its patriarchs were descendants from the old patriarchal line (Abouna line). It therefore had a legitimacy in the eyes of many East Syrians that the Amid patriarchate could never have. Rome supported the Amid patriarchs as its Catholic bridgehead in the East Syriac Church, but the goal was to gain the line of the Mosul patriarchate for communion with the Catholic Church. This was finally achieved early in the nineteenth century, in the person of Yohannan Hormizd from the old patriarchal family.

By the end of the eighteenth century, under the influence of the Amid patriarchate and with the help of Capuchins and Dominicans, nearly all the East Syrians of the Mosul region were in communion with the Catholic Church. Catholicos-Patriarch Eliya XII Denkha (1722–1778) in Rabban Hormizd realized the growing strength of the Catholic movement, and wrote several letters to Rome expressing the desire for union, but Patriarch Joseph III of Amid hindered its becoming a reality. When the nephew of the catholicos took office as Eliya XIII Isho’yahb (1778–1804), his cousin Yohannan Hormizd, metropolitan of Mosul, vehemently opposed him. Most of their conflicts concerned the connections with Rome. Hormizd considered himself as a Catholic from 1778 onwards; however, the Catholic Church did not yet recognize him as patriarch, confirming him only as metropolitan of Mosul and patriarchal administrator. The reasons were doubts about the sincerity of his conversion and the opposition from the patriarchal line of Amid under Augustine Hindi.

In 1804 Patriarch Eliya XIII Isho’yahb died, not having been reconciled with his cousin Hormizd and without having a nephew to succeed him. However, opposition against Yohannan Hormizd came now from the monks of Rabban Hormizd and the newly established order under Gabriel Dambo. They accepted Augustine Hindi, “the Patriarch of Amid.” Further, Latin missionaries began to report disquieting rumours about the performance of Hormizd’s duties. The precarious relations with the Vatican resulted in his suspension in 1812, when Augustine Hindi was appointed apostolic delegate for the “Patriarchate of Babel.” This suspension lasted for six years and was renewed in 1818. The conflict came to an end after the death of Joseph V Hindi. Yohannan Hormizd was finally confirmed by Pope Pius VIII as the only “Patriarch of Babylon for the Chaldeans” on 5 July 1830. Thus, the patriarchates of Amid and Mosul were reunited. Since that time, the old patriarchal line of the Church of the East has been in communion with the Roman Catholic Church.


  1. From the nineteenth century to today

To prevent Yohannan Hormizd’s attempt to preserve the patriarchal succession within his family, Rome appointed the metropolitan of Salmas, Nicholas Zaya (1838–1848), as his coadjutor with the right of succession. In 1844 Nicholas I was the first to obtain an Ottoman imperial firman recognizing him as the patriarch of the “Chaldeans.” Thus the Chaldean Church was legally recognized as a nation (millet).

Nicholas was succeeded by the energetic Joseph VI Audo (1848–1878), a staunch defender of the rights of the Eastern patriarchs at the First Vatican Council (1870) and known for his attempts to assert the Chaldean right to send bishops to the Malabar Christians. Audo laid the foundations for the remarkable growth of the Chaldean Church in the decades before the First World War. He was convinced that the Chaldean Church needed educated priests and bishops. Therefore, he established the Chaldean Patriarchal Seminary of St. Peter in Mosul in 1866, supported the monks of Notre Dame des Semences near Alqosh, and gave permission to establish the Syro-Chaldean Seminary of St. John, founded by the Dominicans in 1878. At the end of the long rule of his successor Patriarch Emmanuel II Thomas (1900–1947), the majority of the East Syriac Christians formed the Chaldean Church. This was the result of intense missionary work among the villages in the north.

During the traumatic events of the First World War (1914–1918) the Qudshanis patriarchate lost its homeland and about a third of its population had perished. Thousands of Chaldeans in Seert, Diyarbakir, Gazireh, the Lake Van area and Mardin were also victims of the massacres by the Ottoman troops. The Chaldean dioceses of Seert, Gazireh, Diyarbakir and Van were ruined. However, the Mosul region and other Chaldean regions were not affected, thanks to the efforts of Patriarch Emmanuel II Thomas.

In 1947, Joseph VII Ghanima (1947–1958) transferred the patriarchate to Baghdad, the capital of the Hashemite Kingdom, to be closer to the key offices and to his flock. Many families had left their villages and moved to Baghdad, looking for jobs, security and education for their children in the universities. His successor Paul II Cheikho (1958–1989) was elected patriarch at the time of political upheavals in Iraq. During his nearly thirty years of tenure, he had to guide the Chaldean Church through three revolutions (1958, 1963, 1968), three regimes, the Kurdish uprising and the long Iran-Iraq War (1980–1988). During the clashes between the Kurds and the Iraqi army, which lasted until 1975, many Christian villages were burned down and churches destroyed. In 1969, Rabban Hormizd Monastery was plundered. This period is noted for the dramatic movement of Christians from the north of Iraq to the south, into large cities. Patriarch Paul II Cheikho constructed more than twenty-five churches in Baghdad to serve the needs of the Chaldean community.

In 1989 the Chaldean synod elected Raphael Bidawid (1989–2003) as patriarch. He became the head of the Church after the exhausting Iran-Iraq war. However, his patriarchate saw the times of the Iraqi invasion of Kuwait and the defeat of Iraq in the First Gulf War (1990–1991), the regime of Saddam Hussein, the hopeless economic situation of the time of the embargo, the destruction of Iraqi society and the Second Gulf War in 2003, with the removal of the Ba’ath party from power. The emigration of Christians and the geographical shift changed the configuration of the Christian communities. In the last thirty years, Christians have dropped from 20% of the Iraqi population to only 5%. The Chaldean diaspora now represents a significant element of the Church, with bishops in the Middle East for the refugees in that region, and with other bishops for those who immigrated to Australia, New Zealand, Europe and North America.

A landmark of ecumenism was set by the Common Christological Declaration, signed by the Patriarch Dinkha IV Khanania of the Assyrian Church and Pope John Paul II on 11 November 1994. This laid the basis for bilateral relations between the Chaldean Church and the Assyrian Church of the East. Dinkha IV and Raphael I signed a Joint Patriarchal Statement (1996) that initiated a new common process of dialogue and cooperation. In October 2001 the Pontifical Council for Promoting Christian Unity published “Guidelines for the Admission to the Eucharist between the Chaldean Church and the Assyrian Church of the East,” reacting to the pastoral necessity as a result of emigration.

In December 2003 Emmanuel-Karim Delly was elected patriarch for the about 750,000 faithful Chaldean Christians worldwide. Most of them still live in Iraq—75% of them in Baghdad. They are the third largest group in that country, after the Arabs and the Kurds. They are working in education and business, and although they are a small group, their presence is much appreciated. They are generally enlightened and open-minded, and a factor of understanding and harmony among different religious and ethnic groups of Iraqi society.

The Chaldean Church has eight dioceses in Iraq, including the Patriarchal See of Baghdad, Basra, Kirkuk, Mosul, Erbil, Zakho, Alqosh and Amadiya. The other dioceses are in Iran, Lebanon, Syria, Egypt and Turkey, while two are in the United States. The Chaldean community in Essen (Germany) is one of the most numerous groups of Chaldean Catholic faithful, spread throughout France, Germany and northern Europe, especially after the various conflicts, lack of security and instability in Iraq.

   On 28 January 2013 the synod of bishops of the Chaldean Church, meeting in Rome, canonically elected as patriarch of Babylon of the Chaldeans Louis Sako, former archbishop of Kirkuk of the Chaldeans. The new patriarch, succeeding Emmanuel III Delly, has taken the name Louis Raphaël I Sako.


  1. Formation of clergy and religious


8.1. St. Peter’s Chaldean Patriarchal Seminary in Baghdad


The founder of this vital institute was the Chaldean Lazarist Raphael Petros Al Maziji from Diyarbakir (Turkey). As most of the priests did not have an appropriate theological and pastoral formation, he was aware of the need for proper education of the local clergy. He founded the institute in Mosul in 1866, during the reign of Patriarch Joseph Audo. Al Maziji also bought a printing press and published many liturgical and religious books. The seminary gave the Chaldean Church most of its bishops and priests. In 1960, the patriarchal synod with Paul II Cheikho decided to transfer the seminary to Baghdad for political and economic reasons. The seminary building was constructed in Medinat Al-Mikanik. From 1960 to 1963 its direction was entrusted to some Indian Malabar Carmelite fathers, while other congregations, especially Belgian Redemptorists, were helping as teachers. American Jesuits, working in their Baghdad College and University since the 1930s, were expelled in 1968 by the Ba’ath regime. Since that time the local clergy runs the minor and major seminary.


8.2. Babel College


In 1990, Patriarch Raphael I Bidawid founded the faculty of theology, “Babel College,” situated in front of the major seminary. Its purpose was to provide a good, deep and open formation to the seminarians, monks, nuns and lay people engaged in religious instruction in the parishes. Because of the First Gulf War, the academic year started only in 1991, under the direction of the outstanding Chaldean scholar Dr. Jousif Habbi.

Criteria for admission state that students should have finished high school before entering the college. The curriculum includes two years of philosophy and four years of theology, before graduating with a bachelor degree. In 1998 the faculty became a pontifical faculty of theology and philosophy.


  1. Religious Orders


9.1. Antonine Order of St. Hormisdas of the Chaldeans


The monastic tradition in this Church goes back to the days of the Persian Empire. The sons and daughters of this tradition are described by the early Syriac Father Aphrahat (circa 345). Subsequently in the sixth century, Mesopotamian monastic life was revived and provided with a body of rules by Abraham of Kashkar († 588). There have been several forms of religious life (asceticism and monasticism), based on the spiritual and mystic writings of Isaac of Nineveh, Martyrios Sahdona, and John of Delyatha, its best known representatives with their works translated into European languages.

In the seventh century, pioneers from monasteries of Mount Izla founded several monasteries in the plain of Mosul, such as Mar Elijah, Mar Michael near Mosul and Mar Abraham in Batnaya. Rabban Hormizd founded a monastery near Alqosh that still bears his name. During the reign of the Abbasids, monastic life flourished. The monks educated the faithful, transmitted scholarship and kept the East Syriac tradition by transcribing manuscripts. However, monastic life declined during the Mongol and Ottoman periods.

In the nineteenth century a Chaldean merchant from Mardin entered a Maronite monastery in Lebanon. This was the visionary Gabriel Dambo, who after a few years left Lebanon and reached Iraq. In 1808 he revived Chaldean monastic life at Rabban Hormizd Monastery in Alqosh near Mosul. On the basis of his experience with the Maronite Antonines, he introduced the rule of St. Antony. Dambo’s revival of monasticism had been partly intended to supply the Church with a well-educated clergy. Therefore he established in the historic monastery a seminary that attracted many young men from the surrounding villages. Already in the 1820s several monks of the monastery had become bishops, and others were sent out as priests to the Chaldean villages. Other monks were scribes and copied manuscripts, thereby preserving the East Syriac heritage. In its beginnings, the community was troubled by the inner feuds of the Church of the East, during the times that Yohannan Hormizd opposed Gabriel Dambo. The disputes were resolved by the settlement of 1830, by which Hormizd was recognized as patriarch, but the following years, particularly 1832, the monastery became the object of attacks from the Kurds. Dambo, who had returned from Rome (where he was seeking approval for his community), was among the hundreds of Chaldeans killed during the massacre carried out by the Pasha of Rawandiz in 1834. His body, initially buried in the church of Mar Mikha in Alqosh, was transferred to Rabban Hormizd Monastery in 1843. On 28 September 1845, Pope Gregory XVI finally approved the constitutions of the order by the brief Monachorum instituta.

In 1968, because of the unstable political situation, the monks built a new monastery, St. Antony, in Baghdad. The young brothers receive their theological formation in Babel College. Since 1999 the Chaldean Monks publish the magazine Rabbanoutha, treating monastic and historic subjects.


9.2. Chaldean Congregation of the Daughters of Mary Immaculate


Since the advent of Islam, Chaldeans no longer had any female congregations. At the end of the nineteenth century, Dominican nuns from Tours in France came to Mesopotamia as missionaries and nurses. In the years after communion with Rome was established, there was a desire to have local Chaldean nuns, but the political circumstances prevented this project from being realized. Finally, two Chaldean priests, Antoun Zabuni and Philippe Shauriz, founded the first religious congregation for women in Iraq. Its purpose was to take care of education, run schools and orphanages and provide religious instruction in the parishes. With the blessing of Patriarch Emmanuel II Thomas the patriarchal congregation began on 7 August 1922. The number of nuns increased, with missions all over Iraq and in the diaspora. Today, in a very difficult situation, they are engaged in a generous service to the Iraqi population and offer their assistance not only to the Christian community but also to Muslims.


9.3. Congregation of the Daughters of the Sacred Heart of Jesus


In 1911 a pioneer priest, Fr. Ablahad Raes, originally from a remote village of northern Iraq, founded a female congregation to take care of women in the many villages of the diocese of Amadiya. The nuns would teach religion to women, help them to educate their children and promote the conditions of women in that mountainous area. Bishop Francis Dawoud approved the constitutions in the same year.

In 1961 the sisters had to leave the diocese together with many Christians because of the Kurdish War. They settled in the edifices of St. Peter’s Seminary in Mosul. Their number steadily increased. In 1984 President Saddam Hussein built them a proper house, Deir en-Nasr, in the el-Arabi quarter of Mosul.

On 6 January 1998, Patriarch Raphael I Bidawid recognized the community as a patriarchal congregation. He is therefore considered as the second founder. The sisters have three houses in Baghdad, two in Amadiya (Mangesh and Baradesh) and one in Mosul and Erbil. Since 1999 they have opened a house in France and a mission in Georgia.





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Statistics and maps


Patriarchal Church of Babylon of the Chaldeans

628,405 faithful (2017)




Egypt (p. XXX):

Cairo, Le Caire, eparchy




Canada (p. XXX):

Mar Addai of Toronto, eparchy


United States of America (p. XXX):

Saint Peter the Apostle of San Diego, eparchy

Saint Thomas the Apostle of Detroit, eparchy




Iran (p. XXX):

Ahwaz, archeparchy

Salmas, Shahpour, eparchy

Tehran, Teheran, metropolitan archeparchy

Urmyā, Urmia, Rezayeh, metropolitan archeparchy

Iraq (p. XXX):

Alqosh, Alquoch, eparchy

Amadiya-Zaku, Amadia and Zaku, Amadiyah, Zākhō, eparchy

Aqrā, Akra, eparchy

Baghdad, patriarchal metropolitan archeparchy

Bassorah, Basra, archeparchy

Erbil, Arbil, archeparchy

Kirkuk, Kerkūk, metropolitan archeparchy

Mosul, Mossul, archeparchy



Jordan, territory dependent on the patriarch


Lebanon (p. XXX):

Bairut, Beirut, eparchy



Jerusalem, Gerusalemme, territory dependent on the patriarch


Syria (p. XXX):

Aleppo, Alep, Beroea, Halab, eparchy


Turkey (p. XXX):

Diyarbakir, Diarbekir, Amida, archeparchy




Australia and New Zealand (p. XXX):

Saint Thomas the Apostle of Sydney, eparchy