A Qaysi from the Jazira,[1] Umar claimed to belong to the traditional Arab nobility by virtue of his maternal grandfather, who was supposedly chief of the Banu Uday branch of the Fazara tribe.
[4][8] Al-Harashi proved a capable commander against the Soghdian rebels, but too harsh in his dealings with domestic quarrels, even executing prisoners whose life Umar had guaranteed.
[10] In the wake of the suppression of Yazid ibn al-Muhallab's rebellion in Iraq, the province was held down in virtual occupation by the regime's trusted Qaysi Syro-Jaziran troops, and Umar appointed almost exclusively his fellow north Arab Qaysis to provincial governorships, virtually excluding the south Arab (Yamani) tribes, traditionally dominant in Iraq, from power.
[6][8][11] Indeed, when Caliph Hisham ibn Abd al-Malik came to power in 724, one of his first acts was to dismiss Umar from his post, and replace him with Khalid al-Qasri, whose tribal origin made him neutral in the Qays–Yaman conflict.
[12] As a result of his fervent championship of the Qays in the Qays–Yaman conflict, both he, and his son, Yazid, who would serve as governor of Iraq under Marwan II, receive a very negative treatment in the sources.