e
Persians, while Mesopotamia returned to its old condition of a Roman
province.

The peace made between Philip and Sapor was followed by an interval of
fourteen years, during which scarcely anything is known of the condition
of Persia. We may suspect that troubles in the north-east of his empire
occupied Sapor during this period, for at the end of it we find Bactria,
which was certainly subject to Persia during the earlier years of
the monarchy, occupying an independent position, and even assuming an
attitude of hostility towards the Persian monarch. Bactria had, from a
remote antiquity, claims to pre-eminence among the Aryan nations. She
was more than once inclined to revolt from the Achaemenidae; and during
the later Parthian period she had enjoyed a sort of semi-independence.
It would seem that she now succeeded in detaching herself altogether
from her southern neighbor, and becoming a distinct and separate power.
To strengthen her position she entered into relations with Rome, which
gladly welcomed any adhesions to her cause in this remote region.

Sapor's second war with Rome was, like his first, provoked by himself.
After concluding his peace with Philip, he had seen the Roman world
governed successively by six weak emperors, of whom four had died
violent deaths, while at the same time there had been a continued series
of attacks upon the northern frontiers of the empire by Alemanni,
Goths, and Franks, who had ravaged at their will a number of the finest
provinces, and threatened the absolute destruction of the great monarchy
of the West. It was natural that the chief kingdom of Western Asia
should note these events, and should seek to promote its own interests
by taking advantage of the circumstances of the time. Sapor, in A.D.
258, determined on a fresh invasion of the Roman provinces, and, once
more entering Mesopotamia, carried all before him, became master of
Nisibis, Carrhae, and Edessa, and, crossing the Euphrates, surprised
Antioch, which was wrapped in the enjoyment of theatrical and other
representations, and only knew its fate on the exclamation of a couple
of actors "that the Persians were in possession of the town." The
aged emperor, Valerian, hastened to the protection of his more eastern
territories, and at first gained some successes, retaking Antioch, and
making that city his headquarters during his stay in the East. But,
after this, the tide turned. Valerian entrusted the whole conduct of the