The roots of the genocide lie in the collapse of the Ottoman Empire. In the empire, religious minority communities, like the Christian Armenians, were allowed to maintain their religious, social, and legal structures, but were often subject to extra taxes or other measures. Concentrated largely in eastern Anatolia, many of them merchants and industrialists, Armenians appeared markedly better off in many ways than their Turkish neighbours, mainly peasants or ill-paid government functionaries and soldiers.

At the turn of the century, the Ottoman Empire was crumbling at the edges, beset by revolts among Christian subjects to the north and the subject of dissatisfaction with the situation amongst Arab nationalist intellectuals.

In March of 1914, the Young Turks entered World War I as allies of Germany. They attacked to the east, hoping to capture the city of Baku in what would be a disastrous campaign against Russian forces in the Caucuses. They were soundly defeated at the battle of Sarikemish. Armenians in the area were blamed for siding with the Russians and the Young Turks began a campaign to portray the Armenians as a threat to the state. Indeed, there were Armenian nationalists who acted as guerrillas and cooperated with the Russians. They briefly seized the city of Van in the spring of 1915.

Armenians mark the date 24 April 1915, when several hundred Armenian intellectuals were rounded up, arrested, and later executed as the start of the Armenian genocide and it is generally said to have lasted up until 1917. There were 2,133,190 Armenians in the empire in 1914 and only about 387,800 by 1922.

The Young Turks, who called themselves the Committee of Unity and Progress, launched a set of measures against the Armenians, including a law authorizing the military and government to deport anyone they sensed was a security threat. A later law allowed the confiscation of abandoned Armenian property. Armenians were ordered to turn in any weapons that they owned to the authorities. Those in the army were disarmed and transferred into labor battalions where they were either killed or where they worked to death.

There were executions, and death marches of men, women, and children across the Syrian desert to concentration camps with many dying along the way of exhaustion, exposure, and starvation. Much of this was quite well documented at the time by Western diplomats, missionaries, and others, creating widespread wartime outrage against the Turks in the West. Although its allies, Germany and Austria-Hungary, were silent at the time, in later years documents have surfaced from ranking diplomats of these countries and military officers expressing horror at what was going on.