Hundreds of thousands of Armenians died in 1915 at the hands of the Ottoman Turks, whose empire was disintegrating.
Armenia says up to 1.5 million people were killed. Turkey says the number of deaths was much smaller.
Most non-Turkish scholars of the events regard them as genocide – as do more than 20 states, including France, Germany, Canada and Russia, and various international bodies including the European Parliament.
Turkey rejects the term “genocide”, maintaining that many of the dead were killed in clashes during World War One, and that many ethnic Turks also suffered in the conflict.