With extremists battling for control of Iraq's largest oilfield on Tuesday, upping the stakes in a burgeoning war against the central government in Baghdad, Iraq's Christians once again find themselves at risk. Over the past 10 days, the Islamic State of Iraq and Syria (Isis), also known as the Islamic State of Iraq and the Levant, a fundamentalism jihadist group, has streamed across the Nineveh plains of northern Iraq from its bases in eastern Syria, capturing a line of towns and cities, including several with large Assyrian and Chaldean Christian populations. Some 160 Christian families have fled Mosul, Iraq's second largest city, for Christian-inhabited towns and villages in northern Iraq over the past week, according to Associated Press. Hundreds more have left seeking safety in the autonomous Kurdish region to the east. Mosul was home to about 130,000 Christians before the US-led 2003 invasion of Iraq and following last week's Isis takeover, is reported to be almost empty of Christian families. Assyrians are one of the oldest indigenous communities in the region. Their roots in what is today northern Iraq and eastern Syria go back over 2,000 years, with the latter stages of that history increasingly marred by bloodshed. During the dying days of the Ottoman Empire as the first World War unfolded, about 750,000 Assyrians were killed as part of the broader slaughter of Christian Armenians and Greeks in modern-day Syria, Iraq and Turkey. Then in 1933, about 3,000 Assyrian Christians were killed by Iraqi soldiers and Kurds in the northern Iraqi town of Sumel, leading to mass migration across the border to Syria. Hellish time More recently, Christians in Iraq have experienced a hellish time. On Christmas Day last year, 37 people were killed in a series of car bomb attacks close to churches in Baghdad, the Iraqi capital. The wave of kidnappings, bombings and assassinations following the 2003 invasion saw many of the city's Christians flee to northern Iraq where they have lived in relative safety, until now. As a result, Iraq's Christian community is today thought to number just 40 per cent of its pre-2003 figure, and today, in the face of the Isis assault, is on the move again. "Each day we went to bed in fear . . . In our own houses we knew no rest," a Christian woman from Alqosh in northern Iraq told reporters, speaking of the threat from jihadists. The danger to Christians in northern Iraq appears not only in the form of jihadists. With Isis viewed as likely to encounter difficulty in holding on to territory in the face of an impending fight-back from better-equipped government forces, a long-standing threat to the slivers of territory in northern Iraq inhabited by Christians has appeared. Kurdish militias According to the Assyrian International News Agency, a total of 14 Assyrian towns and villages in the north have in the past week fallen under the control of Kurdish militias. Iraq's Kurds have their own designs of expanding territorial control across the north, including to the oil-rich city of Kirkuk which Kurdish peshmerga control since late last week. The peace and stability enjoyed in Iraqi Kurdistan, an autonomous region in the north of the country and home to the country's five million Kurds, has proved a rare bright spot in Iraq's recent history. "The Kurds control now most of the disputed territories," said Wladimir Van Wilgenburg, a columnist with Al Monitor and an expert on Kurdish affairs. "They now almost have their national desired borders, only in Diyala [province] there is still a border with the Iraqi army, the rest of the 1,000km is with the Isis." Syrian threat In Isis-controlled eastern Syria, Christians have fared little better. Last March, the jihadist group announced Christians there must convert to Islam, pay a tax or face death. Churches have been damaged and crosses, paintings and statues burned in Raqqa, a city in Syria's east. Several Syrian and foreign priests have been kidnapped and killed by jihadists in Syria over the past three years. But Christians are preparing to fight back. Their militias today form an important cog in the Syrian regime's fighting force in the shape of National Defence Forces -- groups of civilians armed by the Syrian regime. Iraqi prime minister Nouri al-Maliki has called on civilians to take up arms and fight against Isis; reports say about 600 Christians in the town of Bartella, 20km from Isis-controlled Mosul, are defending their homes with machine guns and other light weapons. With the US and other Western governments slow to become involved in another Iraq quagmire, the threat to Christians and other minorities is set to mount.