Gotarzes, his army not being yet in sufficient force, made the river Corma a line of defence, and though he was challenged to an engagement by taunting messages, he contrived delays, shifted his positions and sent emissaries to corrupt the enemy and bribe them to throw off their allegiance. Izates of the Adiabeni and then Acbarus of the Arabs deserted with their troops, with their countrymen's characteristic fickleness, confirming previous experience, that barbarians prefer to seek a king from Rome than to keep him. Meherdates, stript of his powerful auxiliaries and suspecting treachery in the rest, resolved, as his last resource, to risk everything and try the issue of a battle. Nor did Gotarzes, who was emboldened by the enemy's diminished strength, refuse the challenge. They fought with terrible courage and doubtful result, till Carenes, who having beaten down all resistance had advanced too far, was surprised by a fresh detachment in his rear. Then Meherdates in despair yielded to promises from Parrhaces, one of his father's adherents, and was by his treachery delivered in chains to the conqueror. Gotarzes taunted him with being no kinsman of his or of the Arsacids, but a foreigner and a Roman, and having cut off his ears, bade him live, a memorial of his own clemency, and a disgrace to us. After this Gotarzes fell ill and died, and Vonones, who then ruled the Medes, was summoned to the throne. He was memorable neither for his good nor bad fortune; he completed a short and inglorious reign, and then the empire of Parthia passed to his son Vologeses.