LIBERIUS, pope from 352 to 366, the successor of Julius I., was consecrated according to the Catalogus Liberianus on May 22. His first recorded act was, after a synod had been held at Rome, to write to Constantius, then in quarters at Arles 354), asking that a council might be called at Aquileia with ref erence to the affairs of Athanasius; but his messenger Vincentius of Capua was compelled by the emperor to subscribe a con demnation of the orthodox patriarch of Alexandria. In 355 Liberius was one of the few who, along with Eusebius of Vercelli, Dionysius of Milan and Lucifer of Cagliari, refused to sign the condemnation of Athanasius, which had anew been imposed at Milan by imperial command upon all the Western bishops; the consequence was his relegation to Beroea in Thrace, Felix II. (antipope) being consecrated his successor. On his agreeing to give up the "homoousios," to abandon Athanasius, and to accept the communion of his adversaries, the emperor recalled him from exile; but, as the Roman see was officially occupied by Felix, a year passed before Liberius was sent to Rome. It was the em
peror's intention that Liberius should govern the Church jointly with Felix, but on the arrival of Liberius, Felix was expelled by the Roman people. Neither Liberius nor Felix took part in the council of Rimini (359)• After the death of the emperor Con stantius in 361, Liberius annulled the decrees of that assembly, but, with the concurrence of SS. Athanasius and Hilarius, re tained the bishops who had signed and then withdrawn their ad herence. He died on Sept. 24, 366.
His biographers used to be perplexed by a letter purporting to be from Liberius, in the works of Hilary, in which he seems to write, in 352, that he had excommunicated Athanasius at the instance of the Oriental bishops ; but the document is now held to be spurious. See Hefele, Conciliengesch. i. 648 seq.