The Battle of the Zab occurred between the forces of the Abbasid revolutionaries and the Umayyad Caliphate, culminating in a pivotal confrontation that ultimately led to the overthrow of the Umayyads. The battle took place near the Zab River, an area that would become symbolic of the shift in power from the Umayyad ruling class based in Damascus to the new Abbasid leadership. The Abbasid forces were led by Abu Muslim al-Khorasani, who had galvanized support across the Islamic world by framing their struggle as a fight for justice and equity against the Umayyad elite, who were increasingly unpopular due to their perceived decadence and failure to address the needs of the broader Muslim community.The battle strategy employed by the Abbasids leveraged their knowledge of local geography and superior tactics, allowing them to encircle and defeat the larger Umayyad army. The loss at the Battle of the Zab significantly demoralized the Umayyad forces, leading to a rapid collapse of their political power. This defeat marked the threshold of the Abbasid Revolution, as it paved the way for the establishment of the Abbasid Caliphate. Following the battle, many Umayyad leaders were killed or fled, while Abbasid claims to leadership were solidified, ultimately resulting in a new era in Islamic history characterized by cultural, scientific, and economic flourishing under Abbasid rule.