restrain extravagances and lighten the burdens of his subjects. The war
with Persia which had begun under Constantius had not been concluded and
Julian was fired by the ambition to imitate the career of Alexander the
Great and overthrow the Persian kingdom. After long preparations he began
his attack early in 363 A. D. He succeeded in reaching Ctesiphon where he
defeated a Persian army. But his attempt to penetrate further into the
enemy's country failed for want of supplies, and he was forced to begin a
retreat. On the march up the Tigris valley he was mortally wounded in a
skirmish (26 June, 363 A. D.), and with his death ended the rule of the
dynasty of Constantine the Great.

*Jovian, 363-4 A. D.* The army chose as his successor Jovian, the
commander of the imperial guard. To rescue his forces, Jovian made peace
with Sapor, surrendering the Roman territory east of the Tigris, with part
of Mesopotamia, and abandoning the Roman claim to suzerainty over Armenia.
Julian's enactments against the Christians were abrogated and religious
toleration proclaimed. After a brief reign of eight months, Jovian died at
Antioch in 364 A. D.

IV. THE HOUSE OF VALENTINIAN AND THEODOSIUS THE GREAT: 364-395 A. D.

*Valentinian I and Valens, Augusti, 364 A. D.* At the death of Jovian the
choice of the military and civil officials fell upon Flavius
Valentinianus, an officer of Pannonian origin. He nominated as his
co-ruler his brother, Valens, whom he set over the East, reserving the
West for himself.

Valentinian's reign was an unceasing struggle to protect the western
provinces against barbarian invaders. The emperor personally directed the
defense of the Rhine and Danubian frontiers against the incursions of the
Alemanni, Quadi and Sarmatians, while his able general Theodosius cleared
Britain of Picts, Scots and Saxons, and suppressed a dangerous revolt of
the Moors in Africa. In 375 Valentinian died at Brigetio in the course of
a war with the Sarmatians. Although imperious and prone to violent
outbursts of temper, he had shown himself tireless in his efforts to
protect the empire from foreign foes and his subjects from official
oppression. In this latter aim, however, he was frequently thwarted by the
intrigues of his own officers.

*Gratian and Valentinian II.* As early as 367 Valentinian had appointed as
a third Augustus his eldest son, Gratian, then only seven years old. The
latter now succeeded to the government of t