The Battle of Marj Ardabil or the Battle of Ardabil was a battle fought on the plains surrounding the city of Ardabil in northwestern Iran in AD 730. A Khazar army led by Barjik, the son of the Khazar khagan, invaded the Umayyad provinces of Jibal and Iranian Azerbaijan in retaliation for Caliphate attacks on Khazaria during the course of the decades-long Khazar-Arab War of the early 8th century. Barjik's expedition into northern Iran (and later into Kurdistan and northern Mesopotamia) may have been an attempt to establish Khazar rule south of the Caucasus Mountains.