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 had 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 Macriarius and his son, Quietus, turned his arms once more, about A.D. 263, against the Persians, crossed the Euphrates into Mesopotamia, took Oarrhee 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 ventured to form the siege of 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).

The successes of Odenathus in A.D. 263 were followed by a period of comparative tranquillity.  That ambitious prince seems to have been content with ruling from the Tigris to the Mediterranean, and with the titles of “Augustus,” which he received from the Roman emperor, Gallienus, and “king of kings,” which he assumed upon his coins.  He did not press further upon Sapor; nor did the Roman emperor make any serious attempt to recover his father’s person or revenge his defeat upon the Persians.  An expedition which he sent out to the East, professedly with this object, in the year A.D. 267, failed utterly, its commander, Heraclianus, being completely defeated by Zenobia, the widow and successor of Odenathus.  Odenathus himself was murdered by a kinsman three or four years after his great successes; and, though Zenobia ruled his kingdom almost with a man’s vigor, the removal of his powerful adversary must have been felt as a relief by the Persian monarch.  It is evident, too, that from the time of the accession of Zenobia, the relations between Rome and Palmyra had become unfriendly; the old empire grew jealous of the new kingdom which had sprung up upon its borders; and the effect of this jealousy, while it lasted, was to secure Persia from any attack on the part of either.