Inheriting a declining empire where the authority and status of the Sasanian kings had largely ended, Kavad tried to reorganize his empire by introducing many reforms whose implementation was completed by his son and successor Khosrow I. They were made possible by Kavad's use of the Mazdakite preacher Mazdak leading to a social revolution that weakened the authority of the nobility and the clergy. Because of this, and the execution of the powerful king-maker Sukhra, Kavad was imprisoned in the Castle of Oblivion ending his reign. He was replaced by his brother Jamasp. However, with the aid of his sister and an officer named Siyawush, Kavad and some of his followers fled east to the territory of the Hephthalite king who provided him with an army. This enabled Kavad to restore himself to the throne in 498/9.