The Arab conquest of Iraq and Umayyad domination
Immediate resultant of the Muslim conquest was mass immigration of Arabs from eastern Arabia and Oman. Instead of dispersing and settling throughout the country these new arrivals established two new garrison cities, at Kūfah, close to ancient Babylon, and at Basra in the south. The purpose was that the Muslims should be a distinct community of fighting men and their families living off taxes paid by the local dwellers. In the north of the country, Mosul began to develop as the most significant city and the base of a Muslim governor and garrison. Apart from the Zoroastrian priests and the Persian elite, whose properties were confiscated, majority of the local people were permitted to keep their possessions and their religion.
Iraq now became a part (province) of the Muslim Caliphate, extent of which was from North Africa and later Spain in the west to Sind (present day southern Pakistan) in the east. Initially the capital of the Caliphate was at Medina, but, after the assassination of the third caliph, ʿUthmān ibn ʿAffān, in 656 AD, his successor Ali (the Prophet Muhammad’s cousin and son-in-law), made Iraq his base. In 661, however, ʿAlī was himself murdered in Kūfah, and the Caliphate went into the hands of the rival Umayyad family in Syria. Iraq was now a subordinate province, despite being the wealthiest area of the Muslim world and the one having the largest Muslim population. This situation resulted in unwavering discontent with Umayyad rule that took different forms.
In 680 AD ʿAlī’s son al-Ḥusayn arrived in Iraq from Medina, hopeful that the people of Kūfah would back him. People of Kūfah didn’t support him, and his small vulnerable group of followers was massacred at the Battle of Karbala, but his remembrance lingered on as a strong source of inspiration for all who opposed the Umayyads. In later times the city of Karbala and ʿAlī’s tomb at proximate Najaf became key centres of Shiʿi pilgrimage that are still prominently revered today. The Iraqis got patiently awaited opportunity after the death of the caliph Yazīd I in 683 AD, when the Umayyads faced threats from various quarters. In Kūfah al-Mukhtār ibn Abī ʿUbayd ably supported by many mawālī (non-Arab converts to Islam, who felt they were treated as second-class citizens), took the initiative. Al-Mukhtār was killed in 687 AD, but the Umayyads understood that strict rule was essential. Umayyad rule ended only at the fag end of first half of 8th century.