When Kay Khosrow's unyielding rejection reached Afrasiab, the Turanian king was consumed by rage and inner torment. Desperate to rally his domain, he opened his royal treasuries, showering his warriors with silver, gold, helmet, blade, and crown. But as the dark mantle of night withdrew and the sun blazed across the heavens, the fortress of Gang-Dezh stood bathed in white light like the towering back of a snow-white elephant. War horns resounded from both encampments; the earth hardened beneath the thunder of hooves, and the sky turned to solid ebony beneath clouds of dust.
Kay Khosrow, the righteous and wise monarch, mounted his steed at dawn to inspect the immense battlements. He deployed the Iranian host in four formidable divisions: Rostam was commanded to seal off the side by the sea; Gustahm son of Nowzar held the second flank; the venerable Goudarz commanded the third; while Kay Khosrow himself, surrounded by war elephants, royal drums, and heavy cavalry, took charge of the fourth front. To prevent desperate night raids by the Turanians, the King commanded an immense trench, two spears deep, to be dug entirely around the citadel.
Master engineers and siegecraft experts gathered from Rome, China, and India. Two hundred ballistas, two hundred catapults, and two hundred heavy crossbow engines were mounted at every gate. Under the King's precise orders, miners sapped the foundations of the wall, driving subterranean galleries beneath the heavy masonry, propping them with timber posts, and drenching the wood in black naphtha. Before issuing the final assault, Kay Khosrow retired to a secluded place of prayer. Prostrating himself upon the bare earth like a writhing serpent, he wept before Yazdan, praying: 'O Maker of the World, Thou seest the purity of my intent; overthrow the thrones of sorcerers and grant victory to righteousness!' Rising from prayer, he donned his bright coat of mail and gave the fateful command.
The fires were ignited; black naphtha blazed along the wooden props beneath the walls, burning them like dry firewood. With a roar like thunder, the towering rampart of Gang-Dezh lost its footing and collapsed in a mountain of stone and dust. Turanian defenders tumbled downward like rain. The sky turned lapis lazuli as arrows and catapult stones filled the air. Then Rostam the Avenger rushed forward into the breach, carrying the purple flag emblazoned with the Golden Lion. Behind him marched legions of foot soldiers armed with spears and battle-axes, supported by heavy horsemen. In the ferocious melee that followed, Rostam personally subdued and captured two of Turan's greatest pillars: Garsivaz, the wicked uncle of the King, and Prince Jahan, Afrasiab's brave son.
From the summit of his high palace, Afrasiab looked down upon the cataclysm. Two-thirds of his host lay slaughtered, the rest fled in terror, and war elephants trampled the fallen amidst rising smoke and flames. Broken-hearted, he bade a bitter farewell to his royal glory, his crown, and his throne. Yet, before the victors could reach the palace, Afrasiab escaped into a secret subterranean tunnel built beneath his inner chambers. Taking two hundred chosen noblemen, he vanished into the subterranean dark, emerging far out in the desolate desert, leaving no trace behind.
Kay Khosrow entered the royal palace of Gang-Dezh and seated himself upon the golden throne of Turan. When searches failed to locate the fugitive monarch, Kay Khosrow interrogated Garsivaz and Jahan, but they could shed no light on Afrasiab's hiding place. The King declared to his army: 'When an enemy is reduced to a homeless wanderer, his life and death become as one.' He appointed mobads and scholars to safeguard the royal treasures and issued strict orders that Afrasiab's palace must not be burned, nor should the royal women be harmed or paraded in shame. This mercy ignited resentment among the Iranian soldiers, who muttered that Kay Khosrow was acting like a guest to his grandfather, forgetting the innocent blood of Siyavash and the humiliation of Queen Farangis.
Learning of their discontent, Kay Khosrow summoned his commanders, admonishing them: 'Vengeance must be tempered with justice. Goodness alone endures in this fleeting world.' He then ordered the veiled women of the Turanian royal house to be presented. Led by the senior queen mother and princess maidens bearing censers of burning ambergris and ruby cups, they wept bitterly at the King's feet. The noble matriarch testified how she had wept blood over Siyavash's murder and tried to stay Afrasiab's hand. Kay Khosrow was moved to deep sorrow; he granted full pardon and royal protection to the innocent women and children, commanding his army to cease all looting and bloodshed. The King distributed the vast wealth of Turan among his victorious troops, while chieftains from across the Turanian realm sent gifts, letters of submission, and pledges of fealty to the righteous Emperor of Iran.