The Mobeds and the principal nobles had in vain protested against the spread of the new religion and the patronage lent it by the Court.  At length appeal was made to the chief Mobed, and he was requested to devise a remedy for the existing evils, which were generally felt to have passed the limits of endurance.  The chief Mobed decided that, under the circumstances of the time, no remedy could be effectual but the deposition of the head of the State, through whose culpable connivance the disorders had attained their height.  His decision was received with general acquiescence.  The Persian nobles agreed with absolute unanimity to depose Kobad, and to place upon the throne another member of the royal house.  Their choice fell upon Zamasp, a brother of Kobad, who was noted for his love of justice and for the mildness of his disposition.  The necessary arrangements having been made, they broke out into universal insurrection, arrested Kobad, and committed him to safe custody in the “Castle of Oblivion,” proclaimed Zamasp, and crowned him king with all the usual formalities.  An attempt was then made to deal the new religion a fatal blow by the seizure and execution of the heresiarch, Mazdak.  But here the counter-revolution failed.  Mazdak was seized indeed and imprisoned; but his followers rose at once, broke open his prison doors, and set him at liberty.  The government felt itself too weak to insist on its intended policy of coercion.  Mazdak was allowed to live in retirement unmolested, and to increase the number of his disciples.

The reign of Zamasp appears to have lasted from A.D. 498 to A.D. 501, or between two and three years.  He was urged by the army to put Kobad to death, but hesitated to adopt so extreme a course, and preferred retaining his rival as a prisoner.  The “Castle of Oblivion” was regarded as a place of safe custody; but the ex-king contrived in a short time to put a cheat on his guards and effect his escape from confinement.  Like other claimants of the Persian throne, he at once took refuge with the Ephthalites, and sought to persuade the Great Khan to embrace his cause and place an army at his disposal.  The Khan showed himself more than ordinarily complaisant.  He can scarcely have sympathized with the religious leanings of his suppliant; but he remembered that he had placed him upon the throne, and had found him a faithful feudatory and a quiet neighbor.  He therefore received him with every mark of honor, betrothed him to one of his own daughters, and lent him an army of 30,000 men.  With this force Kobad returned to Persia, and offered battle to Zamasp.  Zamasp declined the conflict.  He had not succeeded in making himself popular with his subjects, and knew that a large party desired the return of his brother.  It is probable that he did not greatly desire a throne.  At any rate, when his brother reached the neighborhood of the capital, at the head of the 30,000 Ephthalites and of a strong body of Persian adherents, Zamasp