Penetrating through them and entering the campaign country beyond, his bands soon began the siege of Cæsarea Mazaca, the greatest city of these parts, estimated at this time to have contained a population of four hundred thousand souls. Demosthenes, the governor of Cæsarea, defended it bravely, and, had force only been used against him, might have prevailed; but Sapor found friends within the walls, and by their help made himself master of the place, while its bold defender was obliged to content himself with escaping by cutting his way through the victorious host. All Asia Minor now seemed open to the conqueror; and it is difficult to understand why he did not at any rate attempt a permanent occupation of the territory which he had so easily overrun. But it seems certain that he entertained no such idea.
Devastation and plunder, revenge and gain, not permanent conquest, were his objects; and hence his course was everywhere marked by ruin and carnage, by smoking towns, ravaged fields, and heaps of slain. His cruelties have no doubt been exaggerated; but when we hear that he filled the ravines and valleys of Cappadocia with dead bodies, and so led his cavalry across them; that he depopulated Antioch, killing or carrying off into slavery almost the whole population; that he suffered his prisoners in many cases to perish of hunger, and that he drove them to water once a day like beasts, we may be sure that the guise in which he showed himself to the Romans was that of a merciless scourge—an avenger bent on spreading the terror of his name, not of one who really sought to enlarge the limits of his empire. During the whole course of this plundering expedition, until the retreat began, we hear but of one check that the bands of Sapor received. It had been determined to attack Emesa, one of the most important of the Syrian towns, where the temple of Venus was known to contain a vast treasure. The invaders approached, scarcely expecting to be resisted; but the high-priest of the temple, having collected a large body of peasants, appeared in his sacerdotal robes at the head of a fanatic multitude armed with slings, and succeeded in beating off the assailants. Emesa, its temple, and its treasure escaped the rapacity of the Persians; and an example of resistance was set, which was not perhaps without important consequences.
For it seems certain that the return of Sapor across the Euphrates was not effected without considerable loss and difficulty. On his advance into Syria he had received an embassy from a certain Odenathus, a Syrian, or Arab chief, who occupied a position of semi-independence at Palmyra, which through the advantages of its situation, had lately become a flourishing commercial town. Odenathus sent a long train of camels laden with gifts, consisting in part of rare and precious merchandise, to the Persian monarch, begging him to accept them, and claiming his favorable regard on the ground that he had hitherto refrained from all acts of hostility against the Persians. It appears that Sapor took offence at the tone of the communication, which was not sufficiently humble to please him. Tearing the letter to fragments and trampling it beneath his feet he exclaimed: "Who is this Odenathus, and of what country, that he ventures thus to address his lord? Let him now, if he would lighten his punishment, come here and fall prostrate before me with his hands tied behind his back. Should he refuse, let him be well assured that I will destroy himself, his race, and his land." At the same time he ordered his servants to cast the costly presents of the Palmyrene prince into the Euphrates.
This arrogant and offensive behavior naturally turned the willing friend into an enemy. Odenathus, finding himself forced into a hostile position, took arms and watched his opportunity. So long as Sapor continued to advance he kept aloof. As soon, however, as the retreat commenced, and the Persian army, encumbered with its spoil and captives, proceeded to make its way back slowly and painfully to the Euphrates, Odenathus, who had collected a large force—in part from the Syrian villages, in part from the wild tribes of Arabia—made his appearance in the field. His light and agile horsemen hovered about the Persian host, cut off their stragglers, made prize of much of their spoil, and even captured a portion of the seraglio of the great king.
The harassed troops were glad when they had placed the Euphrates between themselves and their pursuer, and congratulated each other on their escape. So much had they suffered and so little did they feel equal to further conflicts that on their march through Mesopotamia they consented to purchase the neutrality of the people of Edessa by making over to them all the coined money that they had carried off in their Syrian raid. After this it would seem that the retreat was unmolested, and Sapor succeeded in conveying the greater part of his army, together with his illustrious prisoner, to his own country.
With regard to the treatment that Valerian received at the hands of his conqueror it is difficult to form a decided opinion. The writers nearest to the time speak vaguely and moderately, merely telling us that he grew old in his captivity and was kept in the condition of a slave. It is reserved for authors of the next generation to inform us that he was exposed to the constant gaze of the multitude, fettered, but clad in the imperial purple; and that Sapor, whenever he mounted on horseback, placed his foot upon his prisoner's neck. Some add that when the unhappy captive died, about the year a.d. 265 or 266, his body was flayed and the skin inflated and hung up to view in one of the most frequented temples of Persia, where it was seen by Roman envoys on their visits to the great king's court.
It is impossible to deny that oriental barbarism may conceivably have gone to these lengths; and it is in favor of the truth of the details that Roman vanity would naturally have been opposed to their invention. But, on the other hand, we have to remember that in the East the person of a king is generally regarded as sacred, and that self-interest restrains the conquering monarch from dishonoring one of his own class. We have also to give due weight to the fact that the earlier authorities are silent with respect to any such atrocities, and that they are first related half a century after the time when they are said to have occurred.
Under these circumstances the scepticism of Gibbon with respect to them is perhaps worthy of commendation.
It may be added that oriental monarchs, when they are cruel, do not show themselves ashamed of their cruelties, but usually relate them openly in their inscriptions or represent them in their bas-reliefs. The remains ascribed on good grounds to Sapor do not, however, contain anything confirmatory of the stories which we are considering. Valerian is represented on them in a humble attitude, but not fettered, and never in the posture of extreme degradation commonly associated with his name. He bends his knee, as no doubt he would be required to do, on being brought into the great king's presence; but otherwise he does not appear to be subjected to any indignity. It seems thus to be on the whole most probable that the Roman Emperor was not more severely treated than the generality of captive princes, and that Sapor has been unjustly taxed with abusing the rights of conquest.
The hostile feeling of Odenathus against Sapor did not cease with the retreat of the latter across the Euphrates. The Palmyrene prince was bent on taking advantage of the general confusion of the times to carve out for himself a considerable kingdom, of which Palmyra should be the capital. Syria and Palestine, on the one hand, Mesopotamia, on the other, were the provinces that lay most conveniently near to him and that he especially coveted. But Mesopotamia had remained in the possession of the Persians as the prize of their victory over Valerian, and could only be obtained by wresting it from the hands into which it had fallen. Odenathus did not shrink from this contest. It has been, with some reason, conjectured that Sapor must have been at this time occupied with troubles which had broken out on the eastern side of his empire. At any rate, it appears that Odenathus, after a short contest with Macrianus and his son, Quietus, turned his arms once more, about a.d. 263, against the Persians, crossed the Euphrates into Mesopotamia, took Carrhæ and Nisibis, defeated Sapor and some of his sons in a battle, and drove the entire Persian host in confusion to the gates of Ctesiphon. He even returned to lay siege to that city; but it was not long before effectual relief arrived; from all the provinces flocked in contingents for the defence of the western capital; several engagements were fought, in some of which Odenathus was defeated; and at last he found himself involved in difficulties through his ignorance of the localities, and so thought it best to retire. Apparently his retreat was undisturbed; he succeeded in carrying off his booty and his prisoners, among whom were several satraps, and he retained possession of Mesopotamia, which continued to form a part of the Palmyrene kingdom until the capture of Zenobia by Aurelian, a.d. 273.