Artabanus, having ascended the Parthian throne about B.C. 214, and being anxious to distinguish himself, took advantage of the war raging between Antiochus III., the second son of Seleucus Callinicus, and Achseus, one of his rebel satraps, to advance into Media, and to add to his dominions the entire tract between Hyrcania and the Zagros mountains. Of the manner in which he effected his conquests we have no account; but they seem to have been the fruit of a single campaign, which must have been conducted with great vigor and military skill. The Parthian prince appears to have occupied Ecbatana, the ancient capital of the Median Empire, and to have thence threatened the Mesopotamian countries. Upon receiving intelligence of his invasion, Antiochus levied a vast army, and set out towards the East, with a determination to subjugate all the revolted provinces, and to recover the limits of the old Empire of Nicator. Passing the Zagros chain, probably by way of Behistun and Kermanshaw, he easily retook Ecbatana, which was an open town, and undefended by the Parthians, and proceeded to prepare for a further advance eastward. The route from Ecbatana to the Caspian Gates crosses, of necessity, unless a considerable circuit be taken, some large tracts of barren ground, inlets or bays of the Great Salt Desert of Iran. Artabanus cherished the hope that here the difficulties of the way would effectually bar his enemy’s progress, more especially as his troops were so numerous, and as water was scanty throughout the whole region. The streams which flow from Zagros towards the East are few and scanty; they mostly fail in summer, which, even in Asia, is the campaigning season; and those who cross the desert at this time must depend on the wells wherewith the more western part of the region is supplied by means of _kanats_ or underground conduits, which are sometimes carried many miles from the foot of the mountains. The position of the wells, which were few in number, was known only to the natives; and Artabanus hoped that the Syrian monarch would be afraid to place the lives of his soldiers in such doubtful keeping. When, however, he found that Antiochus was not to be deterred by any fears of this kind, but was bent on crossing the desert, he had recourse to the barbaric expedients of filling in, or poisoning, the wells along the line of route-which the Syrian prince was likely to follow. But these steps seem to have been taken too late. Antiochus, advancing suddenly, caught some of the Parthian troops at their barbarous work, and dispersed them without difficulty. He then rapidly effected the transit, and, pressing forward, was soon in the enemy’s country, where he occupied the chief city, Hecatompylos. Up to this point the Parthian monarch had declined an engagement. No information has come down to us as to his motives; but they may be readily enough conjectured. To draw an enemy far away from his