Any member of a people of undetermined origin who built an empire in eastern Europe between the Adriatic and Baltic seas and the Elbe and Dnieper rivers in the 6th–9th centuries.
Mounted nomads, possibly from Central Asia, they made the Hungarian plain the centre of their empire, from which they intervened in Germanic tribal wars, helped the Lombards overthrow allies of Byzantium, and nearly succeeded in occupying Constantinople in 626. They also fought the Charlemagne in 796. In the early 9th century the Avars were fully incorporated in the Carolingian empire.