LUCIFERO of Cagliari. — Bishop of Cagliari, died, according to St Jerome (De viris ill., 95), around 370–71. Nothing is known of his life and education until 354, when he already appears as bishop of Cagliari and came to Rome offering himself to Pope L. Bero to go as an ambassador to Emperor Constantius II to negotiate on the Arian question. The Pope accepted, and the result of the mission was the convocation in Milan of the Council of 355, in which almost all the bishops, pressured by threats and violence, subscribed to the condemnation of St Athanasius, and only L., Eusebius of Vercelli, and Dionysius of Milan were able to resist; they were therefore arrested and sent into exile. L. was assigned as his place of residence Germanicia in Syria, then transferred to Eleutheropolis in Palestine and later to the Thebaid.
In 361, through the edict of Julian the Apostate, he was able to regain his freedom; but instead of returning to his see, he remained for some time in the East, especially at Antioch, which was plagued by dogmatic and disciplinary strife between the followers of Bishop Meletius and those loyal to the memory of Bishop Eustathius. L. worsened the situation by ordaining Paulinus, leader of the Eustathians, as bishop, refusing to accept the decisions of the Council of Alexandria (362), inspired by a desire for peace, and maintaining his intransigence toward Arians and those who had only recently converted, even after his return to Cagliari. The last years of L.’s life are obscure, and it is difficult to say whether he died in the bosom of the Church or not. In Sardinia he is honored as a saint, and even today his feast is celebrated in the dioceses of Cagliari and Oristano with the Mass *de Commune Doctorum*.
During his exile between 356 and 361, L. composed a series of polemical treatises against Emperor Constantius, namely: *Pro s. Athanasio* or *Quia absentem nemo debet iudicare nec damnare*; *De regibus apostaticis*; *De non parcendo in Deum delinquentibus*; *Morientum esse pro Dei Filio*; *De non conveniendo cum haereticis*. They are not rich in doctrinal content and also leave something to be desired in terms of language and style, which is very careless; they abound in scriptural quotations that make them heavy reading; classical culture is also scarce. They are, however, very important both because they reveal the indomitable character of the author and, above all, for the knowledge they provide of the biblical text before the Vulgate edited by St Jerome. It seems that St Athanasius praised them and translated them into Greek. L. also wrote some letters, but those known today are not all authentic or genuine.
The rigorist ideas of L. regarding those who had been stained by Arian errors were embraced by several bishops and ecclesiastics, so much so that after his death mention is made of a sect of Luciferians. This sect had a doctrinal baggage and was also very widespread. The main sources for its knowledge are the treatise by St Jerome: *Altercatio Luciferiani et Orthodoxi* (PL 23, 163–92) for the doctrinal part, and the so-called *Libellus precum* (CSEL, XXXV, pp. 5–44) for the spread of the sect in various regions. According to the *Altercatio*, the Luciferians maintained that in the readmission of Arians to the Church, if they were bishops, they had to renounce all dignity and content themselves with the simple lay state. St Augustine also reports (De haeres., 81) that he had read in an anonymous treatise that the Luciferians also believed that the soul is generated with the body by the parents. The report, however, is uncertain. From the *Libellus*, written by the Luciferian priests Faustinus and Marcellinus and addressed to the emperors Valentinian II, Theodosius, and Arcadius, to implore protection against the hostility of Catholics, it is known that, in addition to Sardinia, the Luciferians were in Spain, where the most prominent representatives were Bishop Gregory of Elvira and a priest named Vincent; at Trier, where the priest Bonosus was; at Ossirinchus, led by Bishop Heraclides; and at Eleutheropolis in Palestine, with Abbess Hermione and her entire monastery. There was also a community of Luciferians in Rome presided over by a certain Bishop Aurelius, succeeded by Ephesius; the two authors of the *Libellus* belonged to II. After L.’s death, his followers continued to make themselves heard for about 20 years; they disappeared between the end of the 4th century and the beginning of the 5th.