The throne of the Kayanians had ever been sustained by the devotion of champions who laid down their lives without claiming the crown. When Rostam and Goudarz endured the dark dungeons of Hamavaran to rescue King Kavus, they never coveted the throne. When the Iranians offered the crown to Rostam, he rejected it with righteous fury, declaring that a warrior's sacred duty is to stand beside the King. Greatness belonged solely to the royal bloodline.
Yet when Bahram Chubin returned victorious over Saveh-Shah and tasted the bitter ingratitude of King Hormozd, ambition took root in his heart. His noble sister Gordiyeh, a woman of profound wisdom, pleaded with him to remember history—how champions like Sufray and Zarmehr served the crown and how usurping royal power would bring ruin upon the house of Mehran. She warned him never to let greed master wisdom. But Yalan-Sineh silenced her counsel, and Bahram pressed forward on his perilous path.
In Rayy, Bahram held magnificent feasts, listening to the songs of Esfandiyar's Seven Labors. He secretly minted silver coins stamped with the name of Prince Khosrow Parviz and sent them to Ctesiphon. When King Hormozd saw the coinage, his paranoia flared into absolute conviction that his son was plotting treason. Hormozd planned to poison Khosrow in his sleep, but a loyal chamberlain exposed the plot. Under cover of darkness, Khosrow fled Ctesiphon, riding hard toward Adurbadagan.
In Adurbadagan, powerful marchlords and chieftains—Badan-e Pirooz, Shir-Zil, Vistahm, Biward, and Khonj—gathered around Khosrow. At the sacred fire temple of Adur Gushnasp, they swore solemn oaths of allegiance to place Khosrow upon the Kayani throne. Meanwhile in Ctesiphon, the enraged Hormozd imprisoned Khosrow's maternal uncles, Bandoi and Gostaham, along with other royal kinsmen, and dispatched Ayin-Goshasp with an army to confront Bahram.
Before departing, Ayin-Goshasp had secured the release of a wicked criminal from his hometown to serve in his ranks. Near Hamadan, an old woman skilled in astrology warned Ayin-Goshasp that his death lay in the hands of that very freed convict. Troubled, Ayin-Goshasp penned a secret letter to King Hormozd asking for an execution order and handed the sealed missive to the convict himself to deliver to court. Along the road, the suspicious man broke the seal, read his own death warrant, and returned in a vengeful fury. Finding Ayin-Goshasp unarmed in his tent, he struck off the commander's head.
The murderer brought the severed head to Bahram Chubin expecting a reward, but Bahram, outraged that an envoy of peace had been slain, ordered the assassin hanged. With Ayin-Goshasp dead, the royal army dissolved into chaos.
When news reached Ctesiphon, King Hormozd shut his doors and sank into despair. Seizing the moment, Bandoi and Gostaham broke their chains, rallied the garrison and citizens of Ctesiphon, and stormed the royal palace. They pulled Hormozd from his golden throne, stripped him of his crown, and drove white-hot irons into his eyes, blinding the monarch and ending his tyrannical reign in dark tragedy.