In the midst of his successes in war, Odenathus was cut off in 250 A.D. by assassination. He had punished his nephew, who killed him in return. Zenobia at once succeeded to the vacant throne, and by her ability governed Palmyra, Syria, and the East. In this task, in which no man could have surpassed her in courage and judgment, she was aided by the counsels of one of the ablest Greeks who had appeared since the days of the famous writers of the classical age. Longinus, who had been her preceptor in the language and literature of Greece, and who, on her ascending the throne, became her secretary and chief counsellor in state affairs, was a literary critic and philosopher whose lucid intellect seemed to belong to the brightest days of Greece. He was probably a native of Syria, born some time after 200 A.D., and had studied literature and philosophy at Athens, Alexandria, and Rome, under the ablest teachers of the age. His learning was immense, and he is the first man to whom was applied the expression "a living library," or, to give it its modern form, "a walking encyclopaedia." His writings were lively and penetrating, showing at once taste, judgment, and learning. We have only fragments of them, except the celebrated "Treatise on the Sublime," which is one of the most notable of ancient critical productions. Under the advice of this distinguished counsellor, Zenobia entered upon a career which brought her disaster, but has also brought her fame. Her husband Odenathus had avenged Valerian, the Roman emperor, who had been taken prisoner and shamefully treated by the Persian king. For this service he was confirmed in his authority by the senate of Rome. But after his death the senate refused to grant this authority to his widow, and called on her to deliver her dominion over to Rome. Under the advice of Longinus the martial queen refused, defied the power of Rome, and determined to maintain her empire in despite of the senate and army of the proud "master of the world." War at once broke out. A Roman army invaded Syria, but was met by Zenobia with such warlike energy and skill that it was hurled back in defeat, and its commanding general, having lost his army, was driven back to Europe in disgrace. This success gave Zenobia the highest fame and power in the world of the Orient. The states of Arabia, Armenia, and Persia, in dread of her enmity, solicited alliance with her. To her dominions, which extended from the Euphrates over much of Asia Minor and to the borders of Arabia, she added the populous kingdom of Egypt, the inheritance of her claimed ancestors. The Roman emperor Claudius acknowledged her authority and left her unmolested. Assuming the splendid title of Queen of the East, she established at her court the stately power of the courts of Asia, exacted from her subjects the adoration shown to the Persian king, and, while strict in her economy, at times displayed the greatest liberality and magnificence.