-el-Ain), recovered Nisibis, and once more
planted the Roman standards on the banks of the Tigris. Sapor hastily
evacuated most of his conquests, and retired first across the Euphrates,
and then across the more eastern river, while the Romans advanced as he
retreated, placed garrisons in the various Mesopotamian towns, and even
threatened the great city of Ctesiphon.

Gordian was confident that his general would gain further triumphs, and
wrote to the senate to that effect; but either disease or the arts of a
rival cut short the career of the victor, and from the time of his death
the Romans ceased to be successful. The legions had, it would seem,
invaded Southern Mesopotamia when the praetorian prefect who had
succeeded Timesitheus brought them intentionally into difficulties by
his mismanagement of the commissariat, and at last retreat was
determined on.

The young Emperor had almost reached his own frontier, when the
discontent of the army, fomented by the prefect, Philip, came to a head.
Gordian was murdered at a place called Zaitha, about twenty miles south
of Circesium, and was buried where he fell, the soldiers raising a
tumulus in his honor. His successor, Philip, was glad to make peace on
any tolerable terms with the Persians; he felt himself insecure upon his
throne, and was anxious to obtain the senate's sanction of his
usurpation. He therefore quitted the East in A.D. 244, having concluded
a treaty with Sapor by which Armenia seems to have been left to the
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 northeast 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 toward the Persian monarch. Bactria had, from a
remote antiquity, claims to preeminence 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 in