A Khazar army led Conquering by Barjik , the son of the Khazar khagan , invaded Attack the Umayyad provinces of Jibal and Adharybaydjian in retaliation for Caliphate attacks Attack 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 Creating Khazar rule south of the Caucasus Mountains .

The victorious Barjik mounted Connect his head on top of the throne from which he commanded Control the battles of his Middle Eastern campaign .

The next year , however , Barjik led Bringing an army to Mosul and was defeated Conquering .

According to Muhammad ibn Jarir al-Tabari and other Arab historians , the Muslims were so enraged by Barjik 's desecration of their commander 's head that they fought Defending with extra vigor .