During Antiquity, it was known as Armenia Major, a central region to the history of Armenians, and one of the four geo-political regions associated with Armenians, the other three being Armenia Minor, Cilicia and Commagene. During the Middle Ages, Turkmens settled in large numbers in the Armenian Highlands.
The region was historically mainly inhabited by Armenians, and minorities of Georgians and Assyrians. The Christian population of the Western half of the region was exterminated during the Armenian Genocide of 1915 and on a smaller scale the Assyrian Genocide.
Their total area is about 400,000 km2. Historically, the Armenian Highlands have been the scene of great volcanic activity. Geologically recent volcanism on the area has resulted in large volcanic formations and a series of massifs and tectonic movement has formed the three largest lakes in the Highland, Lake Sevan, Lake Van and Lake Urmia. The Armenian Highlands are rich in water resources.
Most of the Armenian Highlands is in eastern Turkey, and also includes northwestern Iran, all of Armenia, southern Georgia, and western Azerbaijan. Its northeastern parts are also known as Lesser Caucasus, which is a center of Armenian culture.