Christians in Iraq are one of the oldest, continuous and significant Christian communities. The vast majority of Iraqi Christians are indigenous Assyrians who descend from the ancient Assyria, followed by Armenians then the later Arabs, and a very small minority of Kurdish, Shabaks and Iraqi Turkmen Christians. Christians in Iraq primarily adhere to the Syriac Christian tradition and rites and speak Northeastern Neo-Aramaic dialects, although Turoyo is also present on a smaller scale. Some are also known by the name of their religious denomination as well as their ethnic identity, such as Chaldean Catholics, Chaldo-Assyrians, or Syriacs. Regardless of religious affiliation (Chaldean Catholic Church, Assyrian Church of the East, Syriac Orthodox Church, Syriac Catholic Church, Assyrian Pentecostal Church, etc.) Assyrians Christians in Iraq and surrounding countries are one homogeneous people and separate to other groups in the country, with a distinct history of their own harking back to ancient Assyria.

Christians have inhabited modern-day Iraq for about 2,000 years, tracing their ancestry to ancient Mesopotamia and surrounding lands. The great patriarch Abraham came from Ur (modern-day Nasiriyah), while Isaac's wife Rebecca came from Assyria (in modern-day northwestern Iraq.) Additionally, Daniel lived in Iraq most of his life and the prophet Ezekiel was from southern Iraq and his shrine is located there. Shrines of the prophet Jonah and Saint George are also located there, and a number of other biblical prophets and saints are said to have been from there as well. Adam and Eve are also widely thought to have hailed from Iraq, as the biblical Garden of Eden is often said to have been located in southern Iraq. Syriac Christianity was first established in Mesopotamia, and certain subsets of that tradition (namely the Church of the East and its successor churches) were established in northern and central-southern Iraq. This would become one of the most popular Christian churches in the Middle East and Fertile Crescent and would spread as far east as India and China.

Prior to the Gulf War in 1991, Christians numbered one million in Iraq. This may be an underestimate by half as seen in the 1987 census numbers. Saddam Hussein kept anti-Christian violence under control but Christians were sometimes subjected to "relocation programmes". The predominantly ethnically and linguistically distinct Assyrians were pressured to identify as Arabs. The Christian population fell to an estimated 800,000 during the Iraq War. During the 2013–2017 Iraq War with ISIS rapidly sweeping through western lands, Christian fled as they feared the persecution by the militants, as they were to "execute" any person who did not believe in their Sunni sect. Thousands of Christians fled to Baghdad, where they found refuge and adequate housing, some of whom have chosen to make Baghdad their new permanent home following the full defeat of ISIS in Iraq. Thousands have also fled to other parts of southern Iraq, such as the Shia-majority city of Najaf which housed thousands of Christians in holy Islamic shrines once they fled from ISIS. A large population have also returned to their homes en masse following the defeat of ISIS and were able to celebrate Christian festivals in safety with the protection of the Nineveh Plain Protection Units and its allies. At the same time, the current status of Iraqi Christians is split between the protection of Baghdad and Erbil, in light of their domestic competition. The current number of Assyrians is said to be less than 140,000 in 2024, according to the non-profit Shlama Foundation. Based on broader religious identification, the number of Christians is likely only slightly larger.

Christians in Iraq have been well-integrated and have contributed greatly to Iraq, popularly as scholars, researchers, academics, and economists. Iraqi Christians have also hold high positions in the government, such as Thabit AbdulNour and Tariq Aziz. There is a large population that are entertainers, artists, actresses and singers.

History

Christianity in Iraq has its roots in the conception of the Church of the East in the 5th century AD, predating the existence of Islam in the region of Iraq. Iraqi Christians are predominantly native Assyrians belonging to the Ancient Church of the East, Assyrian Church of the East, Assyrian Pentecostal Church, Assyrian Evangelical Church, Mar Thoma Church, Chaldean Catholic Church, Syriac Catholic Church and Syriac Orthodox Church. In Iraq, there is also a significant population of Armenian Christians whose ancestors had fled from Turkey during the Armenian genocide. The Christian population increased from 550,000 in 1947 (12% of the population of 4.6 million) to 1.4 million in 1987 (8% of the estimated population of 16.3 million). After the 2003 invasion of Iraq, violence against Christians increased, with reports of abduction, torture, bombings, and killings. The Iraq War (2003-2011) displaced much of the remaining Christian community from their homeland as a result of ethnic and religious persecution at the hands of Islamic extremists.

Early Church Christianity was brought to Iraq in the 1st century by Thomas the Apostle and Mar Addai (Addai of Edessa) and his pupils Aggai and Mari. Thomas was one of the Twelve Apostles while, according to tradition, Addai was one of the first 70 disciples. Iraq's Eastern Aramaic-speaking Assyrian communities are believed to be among the oldest in the world.

The Assyrian people adopted Christianity in the 1st century and modern-day northern Iraq became the centre of Eastern Rite Christianity and Syriac literature from the 1st century until the Middle Ages. Among the Assyrians, Christianity initially co-existed with the ancient Mesopotamian religion until the latter began to decline in the 4th century.

In the early centuries after the Arab Islamic conquest of the 7th century, Assyria (also known as Athura and Asoristan) was dissolved by the Arabs as a geopolitical entity. However, the indigenous Assyrians (known as Ashuriyun by the Arabs) continued to play an influential role in Iraq as scholars and doctors.

Rise of Islam According to Hirmis Aboona in the period prior to the establishment of Abbasid rule in 750 AD, pastoral Kurds moved into upper Mesopotamia from Persian Azerbaijan, taking advantage of an unstable situation. Cities in northern and northeastern Assyria were raided and attacked by the Kurds of Persian Azerbaijan, "who killed, looted, and enslaved the indigenous population", and the Kurds were moving into several areas in eastern Assyria. The chronicler Ibn Hawqal spoke about the state to which the region of Shahrazoor had been reduced, describing it as a “town, which was overpowered by the Kurds, and whose environs as far as Iraq had been enjoying prosperity”. Another contemporary source described the region of Adiabene thus: "...the plain of Hadyab was entirely inhabited by the Nestorians but the Kurds have occupied it and depopulated it of its inhabitants".Aboona, H. (2008). Assyrians, Kurds, and Ottomans: Intercommunal relations on the periphery of the Ottoman Empire. Amherst, NY: Cambria Press. p. 92 - 96

Later, the Seljuks invaded Mesopotamia with the support of Kurdish chieftains and tribes. They "destroyed whatever they encountered" and captured and enslaved women. The historian Ibn Khaldun wrote that the Kurds "spoiled and spread horror everywhere". In time, the demographic change led to Assyria and much of Greater Armenia effectively becoming Kurdistan.

The Assyrian Church of the East has its origin in what is now southeastern Turkey and Asoristan (Sasanian Assyria). By the end of the 13th century, there were twelve Nestorian dioceses in a strip from Beijing to Samarkand. Northern Iraq remained predominantly Assyrian, Eastern Aramaic-speaking and Christian until the destructions of the 14th-century Muslim warlord of Turco-Mongol descent, Timur (Tamerlane), who conquered Persia, Mesopotamia and Syria. The civilian population was decimated, and the ancient city of Assur was finally abandoned by the Assyrians after a 4000-year history. Timur had 70,000 Christian Assyrians beheaded in Tikrit and 90,000 more in Baghdad.NUPI - Centre for Russian Studies Timur rewarded the Kurds for their support by "settling them in the devastated regions, which until then had been inhabited by the followers of the Church of the East."Aboona, H. (2008). Assyrians, Kurds, and Ottomans: Intercommunal relations on the periphery of the Ottoman Empire. Amherst, NY: Cambria Press. p. 92 - 97

Ottoman rule

In the 16th century, the Ottomans reinforced their eastern frontier with what they considered loyal Sunni Kurd tribes. They settled Kurdish tribes in these regions and in 1583, Sultan Murad III "gave huge provinces to the Kurdish tribe of Mokri". According to Aboona, "many regions with numerous Assyrian and Armenian monuments and monasteries became completely populated by the Kurds after Chaldiran," and Kurdish historians wrote that "the land was cleared at this time, its indigenous inhabitants driven out by force". The Kurdish historian Ali al Qurani affirmed that Sarsing had "been an Assyrian town and that the Kurds who settled there were immigrants from Persian Azerbaijan." Phebe Marr noted that "in the north too, many of the Kurdish tribes of Persia migrated to Iraq". British traveler James Rich observed in northern Iraq the "rapid influx of Kurds from Persia... and that their advance never ceased". He noted that "some ten thousand families, comprising seventy thousand souls, were constantly moving across the border". Southgate also observed the "rapid advance and settlement of the Kurds from Persia into northern Iraq" around that time.Aboona, H. (2008). Assyrians, Kurds, and Ottomans: Intercommunal relations on the periphery of the Ottoman Empire. Amherst, NY: Cambria Press. p. 101-5 Dr. Grant shared an eyewitness account, stating: "Beth Garrnae (the region of Arbil-Kirkuk) once contained a large population of Nestorian Christians, they are now reduced to a few scattered villages... Within the last six years the Koords of Ravandoos and Amadia have successively swept over it.."Aboona, H. (2008). Assyrians, Kurds, and Ottomans: Intercommunal relations on the periphery of the Ottoman Empire. Amherst, NY: Cambria Press. p. 177 In the 17th century, a new epoch began when Emir Afrasiyab of Basra allowed the Portuguese to build a church outside of the city of Basra.

During World War I, the Assyrians of northern Iraq, southeastern Turkey, northeastern Syria and northwestern Iran suffered the Assyrian genocide, which accounted for the deaths of up to 65% of the entire Assyrian population.

Assyrian genocide and post-World War era

In the early 1930s, the Iraqi Arab ministries disseminated leaflets among the Kurds calling them to join the Arabs in massacring Assyrians. This call appealed to Islamic convictions and united Arabs and Kurds against the "infidel" Christians.Sargon George Donabed, Forging a Forgotten History: Iraq and the Assyrians in the Twentieth Century (Croydon, UK: E dinburgh, 2015), and https://etd.ohiolink.edu/!etd.send_file?accession=akron1464911392&disposition=inline ""THE SIMELE MASSACRE AS A CAUSE OF IRAQI NATIONALISM: HOW AN ASSYRIAN GENOCIDE CREATED IRAQI MARTIAL NATIONALISM "" Just before the Simele massacre of August 11, 1933, Kurds began a campaign of looting against Assyrian settlements. The Assyrians fled to Simele, where they were also persecuted. Just after Iraq formally gained independence in 1933, the Iraqi military led by Kurdish general Bakr Sidqi carried out large-scale massacres against the Assyrians in the city of Simele which had beforehand supported the British colonial administration. According to some studies, many eyewitness accounts attested of the many atrocities that Arabs and Kurds perpetrated against Assyrian women.