Hostilities break out again with the Caliphate in the 710s, with raids back and forth across the Caucasus but few decisive battles.
The Khazars, led by a prince named Barjik, invade northwestern Iran and defeat the Umayyad forces at Ardabil in 730, killing the Arab governor Al-Djarrah al-Hakami and briefly occupying the town.
They are defeated the next year at Mosul, where Barjik directs Khazar forces from a throne mounted with al-Djarrah's severed head, and Barjik is killed.
Arab armies led first by the Arab prince Maslama ibn Abd al-Malik and then by Marwan ibn Muhammad (later Caliph Marwan II) pour across the Caucasus and eventually (in 737) defeat a Khazar army led by Hazer Tarkhan, briefly occupying Atil itself.
The instability of the Umayyad regime makes a permanent occupation impossible; the Arab armies withdraw and Khazar independence is re-sserted.
