The young prince accordingly set out, and reached the city of Zeugma in safety.  Here he was joined, not only by a number of the Parthian nobles, but also by the reigning king of Osrhoene, who bore the usual name of Abgarus.  The Parthians were anxious that he should advance at his best speed and by the shortest route on Ctesiphon, and the Roman governor, Cassius, strongly advised the same course; but Meherdates fell under the influence of the Osrhoene monarch, who is thought by Tacitus to have been a false friend, and to have determined from the first to do his best for Gotarzes.  Abgarus induced Meherdates to proceed from Zeugma to his own capital, Edessa, and there detained him for several days by means of a series of festivities.  He then persuaded him, though the winter was approaching, to enter Armenia, and to proceed against his antagonist by the circuitous route of the Upper Tigris, instead of the more direct one through Mesopotamia.  In this way much valuable time was lost.  The rough mountain-routes and snows of Armenia harassed and fatigued the pretender’s troops, while Gotarzes was given an interval during which to collect a tolerably large body of soldiers.  Still, the delay was not very great.  Meherdatos marched probably by Diarbekr, Til, and Jezireh, or in other words, followed the course of the Tigris, which he crossed in the neighborhood of Mosul, after taking the small town which represented the ancient Nineveh.  His line of march had now brought him into Adiabene; and it seemed a good omen for the success of his cause that Izates, the powerful monarch of that tract, declared in his favor, and brought a body of troops to his assistance.  Gotarzes was in the neighborhood, but was distrustful of his strength, and desirous of collecting a larger force before committing himself to the hazard of an engagement.  He had taken up a strong position with the river Corma in his front, and, remaining on the defensive, contented himself with trying by his emissaries the fidelity of his rival’s troops and allies.  The plan succeeded.  After a little time, the army of Meherdates began to melt away.  Izates of Adiabene and Abgarus of Edessa drew off their contingents, and left the pretender to depend wholly on his Parthian supporters.  Even their fidelity was doubtful, and might have given way on further trial; Meherdates therefore resolved, before being wholly deserted, to try the chance of a battle.

His adversary was now as willing to engage as himself, since he felt that he was no longer outnumbered.  The rivals met, and a fierce and bloody action was fought between the two armies, no important advantage being for a long time gained by either.  At length Oarrhenes, the chief general on the side of Meherdates, having routed the troops opposed to him and pursued them too hotly, was intercepted by the enemy on his return and either killed or made prisoner.  This event proved decisive.  The loss of their leader caused the army of Meherdates to fly; and he himself,