Battle of the Great Zab

The Battle of the Great Zab was the decisive engagement that ended Umayyad rule and established the Abbasid Caliphate. The Abbasid revolution had originated in Khurasan, exploiting widespread discontent with Umayyad governance, particularly the marginalisation of non-Arab Muslims. The last Umayyad caliph, Marwan II — a capable military commander — gathered his forces for a final stand at the Greater Zab River in Iraq. The Abbasid force under Abdullah ibn Ali, uncle of the first Abbasid caliph, decisively defeated the Umayyad army. Marwan II fled westward through Palestine and Egypt, where he was eventually killed in a church in Egypt. The Abbasids then hunted down and killed members of the Umayyad family, with the exception of Abd al-Rahman, who escaped to Al-Andalus and established an independent Umayyad emirate there. The battle shifted the political centre of the Muslim world eastward, with the new capital Baghdad replacing Damascus.