Indigenous Christian minorities remain living among the Kurds who historically dominated most of them. At times, these Christians have also come into conflict with their Muslim neighbors, and in modern times they have been used as a fifth column offering an entry into local politics to Western imperialists. During World War I, these Christians suffered heavily, and their numbers have been greatly reduced.
Before the Europeans began their proselytizing activities in modern times, there were three Christian groups living among the Kurds. The Suryani belonged to the Syrian Orthodox or Jacobite Church and lived mainly in the Tor Abdin and Jazire areas of northwestern Kurdistan. They spoke Aramaic or Arabic dialects. The Assyrians belonged to the very different Nestorian Church, also spoke Aramaic dialects, and lived in central Kurdistan in Bahdinan, Hakkari, and also in Urumiya in present-day Iranian Kurdistan. The Armenians with their own ancient church and language constituted by far the largest group of ethnic Christians. During the civil war that followed the overthrow of Saddam Hussein in 2003, the Christians suffered greatly and many were forced into exile or killed to the point that their future in Iraq began to look dim.
Historical Dictionary of the Kurds. Michael M. Gunter.