Battle of Dayr al-Jamajim
The Battle of Dayr al-Jamajim, was fought in 701 CE in central Iraq between the Syrian army under the Umayyad governor of Iraq, Al-Hajjaj ibn Yusuf, against the Iraqi followers of Abd al-Rahman ibn al-Ash'ath, who had rebelled against Al-Hajjaj's overbearing attitude towards the Iraqis. The rebel army was decisively defeated by Al-Hajjaj's Syrian troops. Most of the rebels were captured by the governor of Khurasan, while Ibn al-Ash'ath fled to Zabulistan.
Background
Initially, Ibn al-Ash'ath managed to drive back Al-Hajjaj and even entered Kufa in triumph, leading Caliph Abd al-Malik ibn Marwan to discuss terms with the rebels, but negotiations were rejected by the more hardline rebel leaders. Al-Hajjaj and Ibn al-Ash'ath's troops skirmished with each other for several months before the decisive battle at Dayr al-Jamajim in April 701, where a cavalry charge by the Syrians broke the rebel army. The defeat marked not only the end of the rebellion, as Ibn al-Ash'ath fled with the remnants of his troops to the east, but also of the power and influence of the Iraqi Arabs: Iraq was garrisoned by Syrian troops and came under tight control by the Syrian-dominated Umayyad government. It was not until the Abbasid period and the foundation of Baghdad as the capital that Iraq would regain its prominence.