boundary as separating them, they would constitute a power that could not but be irresistible.  It would be easy for them to reduce under their sway all the barbarous races on the skirts of their empires, and to hold them in subjection by a flexible system of administration and government.  The Roman infantry was the best in the world, and in steady hand-to-hand fighting must be allowed to be unrivalled.  The Parthians surpassed all nations in the number of their cavalry and in the excellency of their archers.  If these advantages, instead of being separated, were combined, and the various elements on which success in war depends were thus brought into harmonious union, there could be no difficulty in establishing and maintaining a universal monarchy.  Were that done, the Parthian spices and rare stuffs, as also the Roman metals and manufactures, would no longer need to be imported secretly and in small quantities by merchants, but, as the two countries would form together but one nation and one state, there would be a free interchange among all the citizens of their various products and commodities.

The recital of this despatch threw the Parthian monarch into extreme perplexity.  He did not believe that the proposals made to him were serious, or intended to have an honorable issue.  The project broached appeared to him altogether extravagant, and such as no one in his senses could entertain for a moment.  Yet he was anxious not to offend the master of two-and-thirty legions, nor even to give him a pretext for a rupture of amicable relations.  Accordingly he temporized, contenting himself with setting forth some objections to the request of Caracallus, and asking to be excused compliance with it.  “Such a union, as Caracallus proposed, could scarcely,” he said, “prove a happy one.  The wife and husband, differing in language, habits, and mode of life, could not but become estranged from one another.  There was no lack of patricians at Rome, possessing daughters with whom the emperor might wed as suitably as the Parthian kings did with the females of their own royal house.  It was not fit that either family should sully its blood by mixture with the other.”

There is some doubt whether Caracallus construed this response as an absolute refusal, and thereupon undertook his expedition, or whether he regarded it as inviting further negotiation, and sent a second embassy, whose arguments and persuasions induced Artabanus to consent to the proposed alliance.  The contemporary historian, Dio, states positively that Artabanus refused to give his daughter to the Roman monarch, and that Caracallus undertook his expedition to avenge this insult; but Herodian, another contemporary, declares exactly the reverse.  According to him, the Roman Emperor, on receiving the reply of Artabanus, sent a new embassy to urge his suit, and to protest with oaths that he was in earnest and had the most friendly intentions.  Artabanus upon this yielded, addressed Caracallus