Before Rustem reached the age of manhood the king of Persia died, and the kingdom fell into the hands of weaker princes. The Tartar chieftain, Afrāsiyāb, improved the opportunity which he long had sought, of making an invasion upon the rich provinces of Persia, and collecting an immense army he marched to the front, under the pretext of avenging old wrongs. “Afrāsiyāb a mighty army raised, And passing plain and river, mountain high, And desert wild, filled all the Persian realm With consternation and universal dread.” The Persian hosts were in confusion, for the Tartar chief was continually threatening the border. The people looked to Zāl as their natural preserver, but Zāl decided to place his boy at the head of the army, for although very young, Rustem had been carefully trained in warlike exercises, and the long line of warrior blood from whence he came, thrilled his veins with martial valor. All the horses of the imperial stables were brought forth, that the young commander might take from them a steed to bear him through the campaign. But Rustem was not content to choose from these, for his eye fell upon a wild horse of wondrous strength and beauty which was the offspring of a demon. After a fearful struggle the magnificent animal was conquered, and placed beneath saddle and rein, when the young warrior rode into the conflict. THE TŪRĀNIAN INVASION. Mihrāb, the ruler of Kabūl, was the leader of one wing of the Persian army, and Gustāhem of the other, while Rustem led the front, and the glorious banner of Kāvah[249] was flung to the breeze. The Tūrānian king rode in black armor at the head of his dark legions, while his ablest generals led the wings and protected the rear of his vast army. There was one terrific onslaught in which it seemed as if heaven and earth had closed in deadly conflict. The clattering of hoofs, the shrill roar of the trumpets and the rattle of brazen drums were mingled with the cries of dying men, while the glittering spear hastened to the deadly work, and the Tartar king believed that the imperial crown of Persia was just within his reach. When the tide of battle ebbed for a moment, Rustem shouted to his father that he intended to engage the hostile monarch in single combat, but Zāl endeavored to dissuade him from so hopeless a task. “My son, be wise and peril not thyself; Black is his banner, and his cuirass black— His limbs are cased in iron—on his head He wears an iron helm—and high before him Floats the black ensign; equal in his might To ten strong men.... Then beware of him. Rustem replied: ’Be not alarmed for me— My heart, my arm, my dagger, are my castle.”