Besides the reigning emperor, Julian alone survived, of all the numerous posterity of Constantius Chlorus. The misfortune of his royal birth involved him in the disgrace of Gallus. From his retirement in the happy country of Ionia he was conveyed under a strong guard to the court of Mediolanum, where he languished above seven months in continual apprehension of suffering the same ignominious death, which was daily inflicted, almost before his eyes, on the friends and adherents of his persecuted family. His looks, his gestures, his silence, were scrutinised with malignant curiosity, and he was perpetually assaulted by enemies whom he had never offended, and by arts to which he was a stranger. But in the school of adversity, Julian insensibly acquired the virtues of firmness and discretion. He defended his honour, as well as his life, against the ensnaring subtleties of the eunuchs, who endeavoured to extort some declaration of his sentiments; and whilst he cautiously suppressed his grief and resentment, he nobly disdained to flatter the tyrant, by any seeming approbation of his brother’s murder. Julian most devoutly ascribes his miraculous deliverance to the protection of the gods, who had exempted his innocence from the sentence of destruction pronounced by their justice against the impious house of Constantine. As the most effectual instrument of their providence, he gratefully acknowledges the steady and generous friendship of the empress Eusebia, a woman of beauty and merit, who, by the ascendant which she had gained over the mind of her husband, counterbalanced in some measure the powerful conspiracy of the eunuchs. By the intercession of his patroness, Julian was admitted into the imperial presence; he pleaded his cause with a decent freedom, he was heard with favour; and, notwithstanding the efforts of his enemies, who urged the danger of sparing an avenger of the blood of Gallus, the milder sentiment of Eusebia prevailed in the council. But the effects of a second interview were dreaded by the eunuchs; and Julian was advised to withdraw for a while into the neighbourhood of Mediolanum, till the emperor thought proper to assign the city of Athens for the place of his honourable exile.
Whilst his hours were passed in studious retirement, the empress, resolute to achieve the generous design which she had undertaken, was not unmindful of the care of his fortune. After an obstinate, though secret struggle, the opposition of the favourite eunuchs submitted to the ascendency of the empress; and it was resolved that Julian, after celebrating his nuptials with Helena, sister of Constantius, should be appointed, with the title of Cæsar, to reign over the countries beyond the Alps.
Although the order which recalled him to court was probably accompanied by some intimation of his approaching greatness, he appeals to the people of Athens to witness his tears of undissembled sorrow, when he was reluctantly torn away from his beloved retirement.
The emperors of the age of Constantine no longer deigned to consult with the senate in the choice of a colleague, but they were anxious that their nomination should be ratified by the consent of the army. On this solemn occasion, the guards, with the other troops whose stations were in the neighbourhood of Mediolanum, appeared under arms; and Constantius ascended his lofty tribunal, holding by the hand his cousin Julian, who entered the same day on the twenty-fifth year of his age. In a studied speech, conceived and delivered with dignity, the emperor represented the various dangers which threatened the prosperity of the republic, the necessity of naming a cæsar for the administration of the West, and his own intention, if it was agreeable to their wishes, of rewarding with the honours of the purple the promising virtues of the nephew of Constantine.
The two princes returned to the palace in the same chariot; and during the slow procession, Julian repeated to himself a verse of his favourite Homer, which he might equally apply to his fortune and to his fears. The twenty-four days which the cæsar spent at Mediolanum after his investiture, and the first months of his Gallic reign, were devoted to a splendid but severe captivity; nor could the acquisition of honour compensate for the loss of freedom.
The protection of the Rhætian frontier, and the persecution of the western church, detained Constantius in Italy above eighteen months after the departure of Julian. Before the emperor returned into the East, he indulged his pride and curiosity in a visit to the ancient capital.