يزدجرد الثالث
the mission of conquering Khurasan was assigned to Ahnaf ibn Qais and Abdullah ibn Aamir. Abdullah marched from Fars and took a short and less frequent route via Rayy. Ahnaf then marched north direct to Merv, in present Turkmenistan. Merv was the capital of Khurasan and here Yazdegerd III held his court. On hearing of the Muslim advance, Yazdegerd III left for Balkh. No resistance was offered at Merv, and the Muslims occupied the capital of Khurasan without a fight.