This emperor was the son of Julius Constantius, and the nephew of Constantine the Great. He studied the rudiments of grammar under the inspection of Mardonius, a eunuch, and a heathen of Constantinople. His father sent him some time after to Nicomedia, to be instructed in the Christian religion, by the bishop of Eusebius, his kinsman, but his principles were corrupted by the pernicious doctrines of Ecebolius the rhetorician, and Maximus the magician.

Constantius, dying the year 361, Julian succeeded him, and had no sooner attained the imperial dignity than he renounced Christianity and embraced paganism, which had for some years fallen into great disrepute. Though he restored the idolatrous worship, he made no public edicts against Christianity. He recalled all banished pagans, allowed the free exercise of religion to every sect, but deprived all Christians of offices at court, in the magistracy, or in the army. He was chaste, temperate, vigilant, laborious, and pious; yet he prohibited any Christian from keeping a school or public seminary of learning, and deprived all the Christian clergy of the privileges granted them by Constantine the Great.

Bishop Basil made himself first famous by his opposition to Arianism, which brought upon him the vengeance of the Arian bishop of Constantinople; he equally opposed paganism. The emperor's agents in vain tampered with Basil by means of promises, threats, and racks, he was firm in the faith, and remained in prison to undergo some other sufferings, when the emperor came accidentally to Ancyra. Julian determined to examine Basil himself, when that holy man being brought before him, the emperor did every thing in his power to dissuade him from persevering in the faith. Basil not only continued as firm as ever, but, with a prophetic spirit foretold the death of the emperor, and that he should be tormented in the other life. Enraged at what he heard, Julian commanded that the body of Basil should be torn every day in seven different parts, until his skin and flesh were entirely mangled. This inhuman sentence was executed with rigor, and the martyr expired under its severities, on June 28, A.D. 362.

Donatus, bishop of Arezzo, and Hilarinus, a hermit, suffered about the same time; also Gordian, a Roman magistrate. Artemius, commander in chief of the Roman forces in Egypt, being a Christian, was deprived of his commission, then of his estate, and lastly of his head.

The persecution raged dreadfully about the latter end of the year 363; but, as many of the particulars have not been handed down to us, it is necessary to remark in general, that in Palestine many were burnt alive, others were dragged by their feet through the streets naked until they expired; some were scalded to death, many stoned, and great numbers had their brains beaten out with clubs. In Alexandria, innumerable were the martyrs who suffered by the sword, burning, crucifixion and stoning. In Arethusa, several were ripped open, and corn being put into their bellies, swine were brought to feed therein, which, in devouring the grain, likewise devoured the entrails of the martyrs, and in Thrace, Emilianus was burnt at a stake; and Domitius murdered in a cave, whither he had fled for refuge.

The emperor, Julian the apostate, died of a wound which he received in his Persian expedition, A.D. 363, and even while expiring, uttered the most horrid blasphemies. He was succeeded by Jovian, who restored peace to the Church.

After the decease of Jovian, Valentinian succeeded to the empire, and associated to himself Valens, who had the command in the east, and was an Arian and of an unrelenting and persecuting disposition.