The Parthians, meanwhile, alarmed at the turn which affairs had taken, left Antigonus to maintain their interests in Palestine, and concentrated themselves in Northern Syria and Commagene, where they awaited the advance of the Romans.  A strong detachment, under Pharnapates, was appointed to guard the Syrian Gates, or narrow pass over Mount Amanus, leading from Cilicia into Syria.  Here Ventidius gained another victory.  He had sent forward an officer named Pompsedius Silo with some cavalry to endeavor to seize this post, and Pompaedius had found himself compelled to an engagement with Pharnapates, in which he was on the point of suffering defeat, when Ventidius himself, who had probably feared for his subordinate’s safety, appeared on the scene, and turned the scale in favor of the Romans.  The detachment under Pharnapates was overpowered, and Pharnapates himself was among the slain.  When news of this defeat reached Pacorus, he resolved to retreat, and withdrew his troops across the Euphrates.  This movement he appears to have executed without being molested by Ventidius, who thus recovered Syria to the Romans towards the close of B.C. 39, or early in B.C. 38.

But Pacorus was far from intending to relinquish the contest.  He had made himself popular among the Syrians by his mild and just administration, and knew that they preferred his government to that of the Romans.  He had many allies among the petty princes and dynasts, who occupied a semi-independent position on the borders of the Parthian and Roman empires.  Antigonus, whom he had established as king of the Jews, still maintained himself in Judaea against the efforts of Herod, to whom Augustus and Antony had assigned the throne.  Pacorus therefore arranged during the remainder of the winter for a fresh invasion of Syria in the spring, and, taking the field earlier than his adversary expected, made ready to recross the Euphrates.  We are told that if he had crossed at the usual point, he would have found the Romans unprepared, the legions being still in their winter quarters, some north and some south of the range of Taurus.  Ventidius, however, contrived by a stratagem to induce him to effect the passage at a different point, considerably lower down the stream, and in this way to waste some valuable time, which he himself employed in collecting his scattered forces.  Thus, when the Parthians appeared on the right bank of the Euphrates, the Roman general was prepared to engage them, and was not even loath to decide the fate of the war by a single battle.  He had taken care to provide himself with a strong force of slingers, and had entrenched himself in a position on high ground at some distance from the river.  The Parthians, finding their passage of the Euphrates unopposed, and, when they fell in with the enemy, seeing him entrenched, as though resolved to act only on the defensive, became overbold; they thought the force opposed to them must be weak or cowardly, and might