But it marks the real declension of the empire, a declension which no personal vigor in the emperor was now sufficient to disguise, that, even in the midst of victory, Aurelian found it necessary to make a formal surrender, by treaty, of that Dacia which Trajan had united with so much ostentation to the empire. Europe was now again in repose; and Aurelian found himself at liberty to apply his powers as a reorganizer and restorer to the East. In that quarter of the world a marvellous revolution had occurred. The little oasis of Palmyra, from a Roman colony, had grown into the leading province of a great empire. This island of the desert, together with Syria and Egypt, formed an independent monarchy under the sceptre of Zenobia. [Footnote: Zenobia is complimented by all historians for her magnanimity; but with no foundation in truth. Her first salutation to Aurelian was a specimen of abject flattery; and her last _public_ words were evidences of the basest treachery in giving up her generals, and her chief counsellor Longinus, to the vengeance of the ungenerous enemy.] After two battles lost in Syria, Zenobia retreated to Palmyra. With great difficulty Aurelian pursued her; and with still greater difficulty he pressed the siege of Palmyra. Zenobia looked for relief from Persia; but at that moment Sapor died, and the Queen of Palmyra fled upon a dromedary, but was pursued and captured. Palmyra surrendered and was spared; but unfortunately, with a folly which marks the haughty spirit of the place unfitted to brook submission, scarcely had the conquering army retired when a tumult arose, and the Roman garrison was slaughtered. Little knowledge could those have had of Aurelian's character, who tempted him to acts but too welcome to his cruel nature by such an outrage as this. The news overtook the emperor on the Hellespont. Instantly, without pause, "like Até hot from hell," Aurelian retraced his steps--reached the guilty city--and consigned it, with all its population, to that utter destruction from which it has never since arisen. The energetic administration of Aurelian had now restored the empire--not to its lost vigor, that was impossible--but to a condition of repose. That was a condition more agreeable to the empire than to the emperor. Peace was hateful to Aurelian; and he sought for war, where it could seldom be sought in vain, upon the Persian frontier. But he was not destined to reach the Euphrates; and it is worthy of notice, as a providential ordinance, that his own unmerciful nature was the ultimate cause of his fate. Anticipating the emperor's severity in punishing some errors of his own, Mucassor, a general officer in whom Aurelian placed especial confidence, assassinated him between Byzantium and Heraclea. An interregnum of eight months succeeded, during which there occurred a contest of a memorable nature. Some historians have described it as strange and surprising. To us, on the contrary, it seems that no contest