Description acceptable. After this multi-year campaign, a prince on the losing side supposedly ran for his life after horsemen left the decapitated body of his brother to rot near a river. The rise of Qaysites like al-Hajjaj ibn Yusuf in the lead-up to this campaign prompted the Yamanites to supply the bulk of its victorious army. This campaign’s victors swore allegiance to al-riḍā, a title which al-Ḥārith ibn Surayj had earlier invoked during his rebellion against the governor Naṣr ibn Sayyār. A leader during this campaign granted himself the title (*) as-Saffah upon entering Kufa. The combination of harsh kharaj and jizya taxes prompted mawālī to band together under the Black Standard during this campaign, which (10[1])began in Khorasan. This campaign ended with Abu Muslim’s victory at the Battle of Zab. For 10 points, name this event that resulted in the creation of the caliphate that succeeded the Umayyads. ■END■ (10[1])