The expulsion of Mosul's Christian community by Islamic extremists on July 18 put an end to nearly 2,000 years of Christian life in Iraq's second-largest city.
The city was first Christianized in the first and second centuries, when it was known as Nineveh and was the remains of the capital of Mesopotamia's ancient Assyrian empire. That was long before the Muslim conquest of the seventh century.
Following the Muslim conquest, the city became majority Muslim but remained home to dozens of cathedrals and churches as well as the tombs of the Old Testament prophet Jonah.
When the Islamic State, formerly known as the Islamic State of Iraq and the Levant (ISIL), ordered Mosul's Christian community of several thousand families this month to convert to Islam, pay a tax for practicing Christianity, or be executed, the entire community reportedly fled en masse.
Today, they have taken shelter in the small Christian towns and villages that dot the vast Nineveh plain around Mosul or sought refuge in the adjoining Kurdish autonomous region.
"For the first time in the history of Iraq, Mosul is now empty of Christians," Louis Raphael Sako, the Baghdad-based Chaldean Catholic patriarch of Babylon, told reporters on July 19.
Those who fled include both Assyrian and Arab Christians and belong to many different churches.
The majority of Assyrian Christians follow the Chaldean Catholic Church, the Syriac Catholic Church, and the Syriac Orthodox Church, while a minority follow the Assyrian Church of the East.
The Arab Christians belong to the Greek Orthodox Church, the Roman Catholic Church, the Chaldean Catholic Church, and the Syriac Orthodox Church, as well as a number of Protestant churches.
The Christians' homes and their places of worship have now been taken over by the Islamic State. "There have been churches taken over and occupied by the Islamic State and the black signature banners of the Islamic State have been hoisted on church properties and a statue of the Virgin Mary was taken down," says Letta Tayler, a researcher with Human Rights Watch, who has compiled witness accounts of the events in northern Iraq.
The expulsion order marks the final blow for a once prosperous urban community that had already seen its ranks decimated by violence since the U.S. overthrow of Saddam Hussein in 2003.
Long before the arrival of the Islamic State, which swept across northern Iraq in early June and has since declared an Islamic caliphate on the territory it controls in Syria and Iraq, Christians in Mosul were systematically targeted in bombings, executions, and kidnappings for ransom by extremists. The attacks by extremist Muslims, who see the Christians as allied by their faith with Western powers and values, have caused thousands to flee the country.
Church leader Sako says that before 2003 there were about 25,000 Christians in Mosul but this number was steadily decreasing. While no precise numbers are available, he told Reuters on July 21 that several thousand families remained in Mosul at the time of the Islamic State's expulsion order.
The same attrition applies to Christian communities across the country. Overall, some 1.5 million Christians reportedly lived in Iraq before the U.S. invasion, but the number has dropped to some 400,000 today.
Iraqi Christian leaders have sought to underline that they believe Iraqi Muslims as a whole remain religiously tolerant and that the extremist groups who target Christians also pose a danger to all Iraqis. "We have lived with our Muslim brothers in Nineveh for centuries in peace and harmony and never exchanged violence on any day," Father Sabah Boutros of St. George's Church in Baghdad told reporters on July 18.
He said the acts of the Islamic State do not represent Muslims but only the group itself "as it launches its terrorist attacks on all without exception."
Christians are among several minorities who are being systematically expelled or killed by the Islamic State.
Human Rights Watch notes that Shi'ite Shabaks and Shi'ite Turkomans have come under particularly harsh treatment, with tens of thousands of families fleeing their communities near Mosul as a result of Islamic State raids. "They have gone in and rounded up [Shi'ite] men by the dozens in their villages, they have pillaged their homes and they have destroyed and desecrated their shrines and mosques," Tayler says.
The Yazidis, a tiny sect that has survived for centuries and whose theology fuses elements of Islam, Christianity, and Zoroastrianism, have also suffered harsh treatment.