Septimius Odaenathus, or Odenatus (Greek: (Hodainathos), Palmyrene אחינל = little ear), the Latinized form of Odainath, was a famous prince of Palmyra, in the second half of the 3rd century AD, who succeeded in recovering the Roman East from the Persians and restoring it to the Empire.
He belonged to the leading family of Palmyra, which bore, in token of Roman citizenship, the gentilicium of Septimius; hence his full name was Septimius Odainath (Vogüé, Syrie centrale, Nos. 23, 28; Cooke, North-Semitic Inscriptions. Nos. 126, 530). It is practically certain that he was the son of Septimius Hairān the "senator and chief of Tadmor", the son. of Septimius Odainath the senator (N.S.I. p. 285). The year when he became chief of Palmyra is not known, but already in an inscription dated AD. 258 he is styled "the illustrious consul our lord" (N.S.I. No. 126). He possessed the characteristic vigour and astuteness of the old Arab stock from which he sprang; and in his wife, the renowned Zenobia, he found an able supporter of his policy.
The defeat and captivity of the emperor Valerian in 260 left the eastern provinces largely at the mercy of the Persians; the prospect of Persian supremacy was not one which Palmyra or its prince had any reason to desire. At first, it seems, Odainath attempted to propitiate the Parthian monarch Sapor I; but when his gifts were contemptuously rejected (Petr. Patricius, 10) he decided to throw in his lot with the cause of Rome. The neutrality which had made Palmyras fortune was abandoned for an active military policy which, while it added to Odainath's fame, in a short time brought his native city to its ruin. He fell upon the victorious Persians returning home after the sack of Antioch, and before they could cross the Euphrates inflicted upon them a considerable defeat.
Then, when two usurping emperors were proclaimed in the East (AD. 261), Odainath took the side of Gallienus the son and successor of Valerian, attacked and put to death the usurper Quietus at Emesa (Höms), and was rewarded for his loyalty by the grant of an exceptional position (A.D. 262). He may have assumed the title of king before; but he now became totius Orientis imperator, not indeed joint-ruler, nor Augustus, but independent lieutenant of the emperor for the East (Mommsen, Provinces, ii. p. 103).
In a series of rapid and successful campaigns, during which he left Palmyra under the charge of Septimius Worod his deputy (N.S.I. Nos. 127-129), he crossed the Euphrates and relieved Edessa, recovered Nisibis and Carrhae, and even took the offensive against the power of Persia, and twice invested Ctesiphon itself, the capital; probably also he brought back Armenia into the Empire. These brilliant successes restored the Roman rule in the East; and Gallienus did not disdain to hold a triumph with the captives and trophies which Odainath had won (A.D. 264).
While observing all due formalities towards his overlord, there can be little doubt that Odainath aimed at independent empire; but during his lifetime no breach with Rome occurred. He was about to start for Cappadocia against the Goths when he was assassinated, together with Herodes his eldest son, by his nephew Maconius ; there is no reason to suppose that this deed of violence was instigated from Rome. After his death (A.D. 266-267) Zenobia succeeded to his position, and practically governed Palmyra on behalf of her young son Wahab-allath or Athenodorus.
