Roman emperor for 18 months, from 361 to 363; was born at Constantinople, his father being a half-brother of Constantine the Great, on whose death most of Julian's family were murdered; embittered by this event, Julian threw himself into philosophic studies, and secretly renounced Christianity; as joint emperor with his cousin from 355 he showed himself a capable soldier, a vigorous and wise administrator; on becoming sole emperor he proclaimed his apostasy, and sought to restore paganism, but without persecuting the Church; though painted in blackest colours by the Christian Fathers, he was a lover of truth, chaste, abstinent, just, and affectionate, if somewhat vain and superstitious; he was killed in an expedition against Persia; several writings of his are extant, but a work he wrote against the Christians is lost (331-363).