In the severity of the winter season, Shahr Barz (or Sarbaraza) deemed himself secure in the walls of Salban; he was surprised by the activity of Heraclius, who divided his troops and performed a laborious march in the silence of the night. The flat roofs of the houses were defended with useless valour against the darts and torches of the Romans: the satraps and nobles of Persia, with their wives and children, and the flower of their martial youth, were either slain or made prisoners. The general escaped by a precipitate flight, but his golden armour was the prize of the conqueror; and the soldiers of Heraclius enjoyed the wealth and repose which they had so nobly deserved. On the return of spring, the emperor traversed in seven days the mountains of Kurdistan, and passed without resistance the rapid stream of the Tigris. Oppressed by the weight of their spoils and captives, the Roman army halted under the walls of Amida; and Heraclius informed the senate of Constantinople of his safety and success, which they had already felt by the retreat of the besiegers. The bridges of the Euphrates were destroyed by the Persians; but as soon as the emperor had discovered a ford, they hastily retired to defend the banks of the Sarus, in Cilicia. That river, an impetuous torrent, was about three hundred feet broad; the bridge was fortified with strong turrets, and the banks were lined with barbarian archers. After a bloody conflict, which continued till the evening, the Romans prevailed in the assault, and a Persian of gigantic size was slain and thrown into the Sarus by the hand of the emperor himself. The enemies were dispersed and dismayed; Heraclius pursued his march to Sebaste in Cappadocia; and at the expiration of three years, the same coast of the Euxine applauded his return from a long and victorious expedition. Instead of skirmishing on the frontier, the two monarchs who disputed the empire of the East aimed their desperate strokes at the heart of their rival. The military force of Persia was wasted by the marches and combats of twenty years, and many of the veterans, who had survived the perils of the sword and the climate, were still detained in the fortresses of Egypt and Syria. But the revenge and ambition of Chosroes exhausted his kingdom; and the new levies of subjects, strangers, and slaves were divided into three formidable bodies. The first army of fifty thousand men, illustrious by the ornament and title of the golden spears, was destined to march against Heraclius; the second was stationed to prevent his junction with the troops of his brother Theodorus; and the third was commanded to besiege Constantinople, and to second the operations of the chagan, with whom the Persian king had ratified a treaty of alliance and partition. THE SIEGE OF CONSTANTINOPLE (626)