 Badi al-zaman, Husayn Bayqarah's son and heir, sought asylum at Ismail's court and induced him to launch a campaign in the east.Shah Ismail reached Khorasan with great speed; Shaybani Khan retreated to Merv castle to await reinforcement from Uzbek tribes.The Safavid army then pretended to retreat, encouraging the Uzbeks to leave the castle in pursuit, only to be ambushed and destroyed by the Qizilbash ("Red Heads") troops of Shah Ismail once they were too far from the castle to regain its safety.