Part I
Whenever Tacitus indulges himself in those beautiful episodes, in which he relates some domestic transaction of the Germans or of the Parthians, his principal object is to relieve the attention of the reader from a uniform scene of vice and misery. From the reign of Augustus to the time of Alexander Severus, the enemies of Rome were in her bosom—the tyrants and the soldiers; and her prosperity had a very distant and feeble interest in the revolutions that might happen beyond the Rhine and the Euphrates. But when the military order had levelled, in wild anarchy, the power of the prince, the laws of the senate, and even the discipline of the camp, the barbarians of the North and of the East, who had long hovered on the frontier, boldly attacked the provinces of a declining monarchy. Their vexatious inroads were changed into formidable irruptions, and, after a long vicissitude of mutual calamities, many tribes of the victorious invaders established themselves in the provinces of the Roman Empire. To obtain a clearer knowledge of these great events, we shall endeavor to form a previous idea of the character, forces, and designs of those nations who avenged the cause of Hannibal and Mithridates.
In the more early ages of the world, whilst the forest that covered Europe afforded a retreat to a few wandering savages, the inhabitants of Asia were already collected into populous cities, and reduced under extensive empires, the seat of the arts, of luxury, and of despotism. The Assyrians reigned over the East, till the sceptre of Ninus and Semiramis dropped from the hands of their enervated successors. The Medes and the Babylonians divided their power, and were themselves swallowed up in the monarchy of the Persians, whose arms could not be confined within the narrow limits of Asia. Followed, as it is said, by two millions of men, Xerxes, the descendant of Cyrus, invaded Greece.
Thirty thousand soldiers, under the command of Alexander, the son of Philip, who was intrusted by the Greeks with their glory and revenge, were sufficient to subdue Persia. The princes of the house of Seleucus usurped and lost the Macedonian command over the East. About the same time, that, by an ignominious treaty, they resigned to the Romans the country on this side Mount Tarus, they were driven by the Parthians, an obscure horde of Scythian origin, from all the provinces of Upper Asia. The formidable power of the Parthians, which spread from India to the frontiers of Syria, was in its turn subverted by Ardshir, or Artaxerxes; the founder of a new dynasty, which, under the name of Sassanides, governed Persia till the invasion of the Arabs. This great revolution, whose fatal influence was soon experienced by the Romans, happened in the fourth year of Alexander Severus, two hundred and twenty-six years after the Christian era. Artaxerxes had served with great reputation in the armies of Artaban, the last king of the Parthians, and it appears that he was driven int