The systematic deportation and mass killing of the Ottoman Empire's Armenian population by the ruling Committee of Union and Progress during the First World War — beginning in April 1915 and recognized by most historians as the first genocide of the twentieth century, with estimates of the dead ranging from roughly 600,000 to 1.5 million, many clustering near or above one million.
On the night of 24 April 1915, Ottoman police in Constantinople arrested some two hundred Armenian writers, teachers, and community leaders. Most were never seen again. That night did not begin the violence, but it marked the moment the empire turned on a people who had lived in its lands for thousands of years. Within a year, much of an Armenian population of roughly 1.5 to 2 million had been deported, massacred, starved, or driven into the Syrian desert, reducing one of the empire’s oldest communities to a remnant. Armenians mark 24 April each year as the day the killing acquired a date.