This is not the place to tell the story of the fortunes of Constantine's three unhappy sons, between whom, contrary to what we might have expected, he divided his empire. Not one of them was at all fit to reign, and Constantius, a cruel and weak man, after a very brief tenure of empire, made way by his opportune death for Julian, who, if he was a pedant and a fanatic, had some real merits. Julian was sole emperor from 361 to 363. His expedition against Persia, then ruled by the war-like and formidable Sapor, was a failure, and cost him his life. Its conclusion was peculiarly inglorious, as Julian's successor, Jovian, had to make peace with the enemy by ceding to him the five provinces east of the Tigris, with the very important city Nisibis, the fortifications of which were the chief bulwark of the Roman empire in those remote regions. This was, indeed, an epoch in Rome's decline, which we may compare with the abandonment of Britain in the following century. It was a confession of weakness. A brave soldier, a native of Illyria, who had fought with glory under Julian in Persia, was now chosen emperor by the imperial ministers in preference to several candidates. This was Valentinian. As was natural, he was the favourite of the army. He was probably nothing more than a brave and capable officer, and may have at once felt that if he was to hold empire he must divide the responsibility. The late disastrous war with Persia may have led him to this decision; perhaps, too, being a plain soldier without much education, he may have thought he was peculiarly ill-fitted to reign over the more highly
