In the Ottoman Empire, repressive actions were consistently carried out against various groups of Assyrians (Nestorians, Chaldeans, Maronites, etc.). For example, in 1843-1847, the massacre of Assyrians then by the Kurdish aga Bedirkhan Bey, about 40 000 Assyrians of Hakkari were killed, in 1860, as a result of the organized by the Turkish authorities, about 10 000 Maronites were killed. Also, many Assyrians were exterminated during the massacre of the Armenian population of Turkey in 1894-1896. However, the planned extermination of the Assyrians began with the entry of the Ottoman Empire into the First World War. The destruction of both the Assyrians and other Christian peoples of Turkey fit perfectly into the Young Turk ideology of "cleansing" Turkey of the non-Turkic element. The methods of extermination of the Assyrians were no different from the methods of genocide of the Armenians, Greeks or Yazidis. First, the men were collected and exterminated through the influence of resistance.

In particular, the tasks of the Turkish army of Assyrians were interrupted. The second step of the Turkish authorities was the arrest and subsequent destruction of the political and cultural elite of the Assyrians. Having dealt in this way with everyone who could resist, the Turks began the deportation of women, old people and children to the deserted Mesopotamia. As a result of hunger, exhaustion, disease and constant attacks by Kurdish troops, only a few of the deportees reached their destinations, where they were still waiting for death from hunger and disease. At the same time, the Turks did not limit the extermination to only the Assyrians - citizens of the Ottoman Empire. During the war, Turkish troops accidentally invaded the territory of neutral Persia, exterminating more than one hundred thousand Christians - Assyrians and Armenians who inhabited the western shore of Lake Urmia.

After the collapse of the Ottoman Empire in World War I, the policy of extermination of the Assyrians was continued by the Turkish nationalist troops under the leadership of Mustafa Kemal, who refused to sign the peace treaty between Turkey and the Entente. Ethnic cleansing of the Assyrians continued even after the signing of the Lausanne Peace Treaty and the establishment of the Turkish Republic in 1923, and not only in Turkey, but also in the border areas of Turkey and Iraq, where Assyrians fled from Turkey. The number of deaths is estimated at 500 000 - 750 000 people. Today, about 3 000 Assyrians live in Turkey, the Turkish government refuses to recognize the national minority.