had
commanded on the Armenian frontier. The first condition proposed by the
ambassador is not at present of a very intelligible nature; that the
city of Nisibis might be established for the place of mutual exchange,
or, as we should formerly have termed it, for the staple of trade,
between the two empires. There is no difficulty in conceiving the
intention of the Roman princes to improve their revenue by some
restraints upon commerce; but as Nisibis was situated within their own
dominions, and as they were masters both of the imports and exports, it
should seem that such restraints were the objects of an internal law,
rather than of a foreign treaty. To render them more effectual, some
stipulations were probably required on the side of the king of Persia,
which appeared so very repugnant either to his interest or to his
dignity, that Narses could not be persuaded to subscribe them. As this
was the only article to which he refused his consent, it was no longer
insisted on; and the emperors either suffered the trade to flow in its
natural channels, or contented themselves with such restrictions, as it
depended on their own authority to establish.

As soon as this difficulty was removed, a solemn peace was concluded and
ratified between the two nations. The conditions of a treaty so glorious
to the empire, and so necessary to Persia Persian, may deserve a
more peculiar attention, as the history of Rome presents very few
transactions of a similar nature; most of her wars having either been
terminated by absolute conquest, or waged against barbarians ignorant of
the use of letters. I. The Aboras, or, as it is called by Xenophon,
the Araxes, was fixed as the boundary between the two monarchies. That
river, which rose near the Tigris, was increased, a few miles below
Nisibis, by the little stream of the Mygdonius, passed under the walls
of Singara, and fell into the Euphrates at Circesium, a frontier
town, which, by the care of Diocletian, was very strongly fortified.
Mesopotomia, the object of so many wars, was ceded to the empire; and
the Persians, by this treaty, renounced all pretensions to that great
province. II. They relinquished to the Romans five provinces beyond the
Tigris. Their situation formed a very useful barrier, and their natural
strength was soon improved by art and military skill. Four of these,
to the north of the river, were districts of obscure fame and
inconsiderable extent; Intiline, Zabdicene, Arzanene