 After the Sasanian disaster, Yazdegerd fled to Isfahan, and raised a small army under a certain military officer named Siyah, who had lost his property to the Arabs.However, Siyah and the rest of the army mutinied against Yazdegerd, and agreed to help the Arabs in return for places to live.Meanwhile, Yazdegerd had arrived in Estakhr, where he tried organizing a base for resistance in the province of Pars.