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.