When news reached Bizhan, ruler of Chach, that Mahuy Suri had seized the throne of royal sovereignty, his heart burned with indignation. Mahuy had dispatched signets and seals to every corner of the realm to demand allegiance, and now he was marching at the head of a battle-ready host toward the rushing waters of the Oxus. Bizhan demanded to know who had dared to bestow the crown upon such a usurper, whereupon the champion Barsam stepped forward to recount the tragic events. Barsam recounted how, after leading horsemen from Chach and capturing the vast spoils of Merv, King Yazdegerd III had been left standing alone. Mahuy had pledged to yield the golden throne, jeweled armlets, and crown of the Emperor to Chach; yet after three days of fierce combat in Merv, once the traitor was laden with riches, he showed no gratitude to Barsam's forces, ignoring them during their two-month stay. Worse still, Mahuy had secretly murdered his own monarch—a ruler so majestic that no Turkic warrior had ever withstood the terror of his crushing mace.
Barsam warned Bizhan that Mahuy's vanguard was swiftly approaching, urging him not to rest while a treacherous usurper roamed free. Outraged by this heinous betrayal, Bizhan assembled a mighty host of battle-hardened Turkic riders from Qajqarbashi, advancing without delay toward Bukhara until the entire plain of Nakhsab was covered in cavalry. Bizhan instructed his commanders to hold their ground and wait for the traitor to cross the river, so that they might avenge the fallen Sasanian monarch on the field of honor. He then inquired whether any brother, son, or daughter of King Yazdegerd remained alive whom they might place upon the throne to restore the royal line. Barsam delivered the devastating truth: the Sasanian lineage was utterly extinct, and the armies of the Arabs held sway over the realm, leaving neither a king nor a Zoroastrian worshiper of God.
Grieving the cruel fate of the realm, Bizhan placed his hands upon his head. Yet as scouts reported that Mahuy's host had crossed the river by boat—raising clouds of dust so dense they veiled the sun—and was organizing its lines at Paykand, Commander Bizhan led his army to the front. When Mahuy Suri beheld the breathtaking array of Chachi mail, golden shields, gleaming helmets, spears, and razor-sharp battle-axes, panic seized his heart and his soul nearly fled his body. Trembling with dread, the usurper drew up his own forces in desperation as the sky turned an indigo gloom and the earth vanished beneath the tread of armaments.