Lucifer (died c. 370) was a bishop of Cagliari, Sardinia, who was a fierce opponent of the heresy of Arianism (q.v.). To further his rigorously orthodox views, he founded the Luciferians, a sect that survived in scattered remnants into the early 5th century.
Lucifer’s opposition to Arianism was tested during the reign of the Roman emperor Constantius II. Himself an Arian, the Emperor had the chief opponent of the heresy, Bishop St. Athanasius the Great, of Alexandria, condemned at a church council at Arelate (later Arles, Fr.), Gaul, in 353. Pope Liberius, disturbed by the council’s bias, asked Lucifer to request a new and impartial imperial council. The result was the Council of Milan (355), at which Athanasius, despite a vigorous defense by Lucifer, was again condemned. Lucifer refused to endorse this decision and was banished to the East, where he wrote five harsh polemical tracts against the emperor. These are of scholarly interest because of their many biblical quotations in Old Latin.
When Constantius died in 361, Lucifer’s exile was ended by an edict issued the next year by the new emperor, Julian the Apostate. Lucifer then went to Antioch, where the church was shattered by factions supporting two men as the rightful bishop. Lucifer deepened the controversy into a schism by consecrating one of the candidates, Paulinus, as bishop. The supporters of his rival, Meletius, did not believe Lucifer had this authority according to canon law, and the church in Antioch remained split until the death of Meletius in 381.
Meanwhile, Lucifer had unalterably opposed a council held in Alexandria in 362 by Athanasius, which had decided to pardon Arians who renounced their views, and he withdrew to his see in Sardinia. There he formed the Luciferians, who promulgated his opinions that all clerics who had been involved in Arianism should be deposed and that any bishop accepting them should be excommunicated. The sect had small groups of adherents in Spain, Gaul, and Rome before it collapsed. It was attacked by St. Jerome in his polemic Altercatio Luciferiani et orthodoxi (“The Dispute of the Luciferian and the Orthodox”).