CHICAGO — The ancient Assyrians considered the Tigris River the division between East and West, and the city I come from in Iraq is called Mosul — connection point, in Arabic — because it connects these two sides. Nineveh, which lay on the eastern bank of the Tigris, was a capital of the great Assyrian empire. When Arabs arrived in the seventh century, they preferred to live at a distance from it, on the western bank, where the modern city of Mosul is today.

Growing up in Mosul, we were told that with the passage of time, the two peoples came to know one another, and exchanged words, languages, customs and rituals. Assyrians came to understand and speak Arabic, Arabs began to understand Assyrian, and in times of need they united. When enemies attacked the city, the Mosul story goes, Assyrians and Arabs joined together to fight off invaders.

These days Mosul is once again a site of combat — but it is far more divided. As I write from my home in Chicago, I have been watching the images on Al Jazeera and other Arabic-language networks: thick black smoke from the oil wells that the Islamic State has set alight clouding the sky over Mosul. Iraqi military forces are trying to reclaim my hometown from the jihadist group that took it over in June 2014. But the Iraqi military is working hand in hand with Iran-backed Shiite militias. Sectarianism is rife; tens of thousands of Sunnis flee their homes in fear. The Mosul I once knew is long gone.

Mosul is an extension of the Nineveh plains, and an early homeland of Christianity. Before the fall of Saddam Hussein, there were dozens of Christian villages thriving in the Nineveh plains. Christians had lived normal lives in Mosul, for the most part, and over time became prominent scholars, doctors, lawyers and writers, and respected, active figures proportionate to their number in society. They made up a little less than a quarter of the city’s population, according to the oldest statistics available, from 1912. I recall that in the days after Iraq gained independence and before a 1958 coup brought Arab nationalists to power, Mosul was represented in Parliament by four Muslim representatives and one Christian.