Short answers, pulled from the story.
The Armenian genocide was the systematic destruction of the Armenian people and identity in the Ottoman Empire during World War I. It was carried out mainly through the mass murder of around one million Armenians on death marches to the Syrian desert and the forced Islamization of others, primarily women and children.
The Armenian genocide was spearheaded by the ruling Committee of Union and Progress, the CUP, with deportations ordered by Talaat Pasha. After the war, an Ottoman Special Military Tribunal sentenced eighteen perpetrators to death, including Talaat, Enver, and Djemal, though only three were executed because the rest had fled.
The Armenian genocide is dated from the 24th of April 1915, when Ottoman authorities arrested and deported hundreds of Armenian intellectuals and leaders from Constantinople. The death marches to the Syrian desert took place across 1915 and 1916.
Around one million Armenians are estimated to have died during the Armenian genocide, with figures ranging from 600,000 to 1.5 million. Between 800,000 and 1.2 million were deported, and contemporaries estimated only about 200,000 were still alive by late 1916.
The CUP feared that Armenians, whose homeland in Anatolia they considered the Turkish nation's last refuge, would break away as the Balkans had. After military defeats including the Battle of Sarikamish, CUP leaders held Armenians collectively guilty of treason and decided to eliminate them to preserve the empire.
Turkey does not recognize the Armenian genocide and maintains that the deportation of Armenians was a legitimate action that cannot be described as genocide. As of the latest count, 34 UN member states, along with the Holy See and the European Parliament, have formally recognized the genocide.