PELAGIUS I, pope from 555 to 561, was a Roman by birth, and first appears in history at Constantinople in the rank of deacon, and as apocrisiarius of Pope Silverius, whose overthrow in favour of Vigilius his intrigues promoted. Vigilius continued him in his diplomatic appointment, and he was sent by the emperor Justinian in 542 to Antioch on ecclesiastical business; he afterwards took part in the synod at Gaza which deposed Paul of Alexandria. He had amassed some wealth, which on his return to Rome he so employed among the poor as to secure for himself great popularity; and, when Vigilius was summoned to Byzantium in 544, Pelagius, now archdeacon, was left behind as his vicar, and by his tact in dealing with Totila, the Gothic invader, saved the citizens from murder and outrage. He appears to have followed his master to Constantinople, and to have taken part in the Three Chapters controversy; in 553, at all events, he signed the " constitutum " of Vigilius in favour of these, and for refusing, with him, to accept the decrees of the fifth general council (the 2nd of Constantinople, 553) shared his exile. Even after Vigilius had approved the comdemnation of the Three Chapters, Pelagius defended them, and even published a book on the subject. But when Vigilius died (June 7, 555), he accepted the council, and allowed himself to be designated by Justinian to succeed the late pope. It was in these circumstances that he returned to Rome; but most of the clergy, suspecting his orthodoxy, and believing him to have had some share in the removal of his predecessor, shunned his fellowship. He enjoyed, however, the support of Narses, and, after he had publicly purged himself of complicity in Vigilius's death in the church of St Peter, he met with toleration in his own immediate diocese. The rest of the western bishops, however, still held aloof, and the episcopate of Tuscany caused his name to be removed from the diptychs. This elicited from him a circular, in which he asserted his loyalty to the four general councils, and declared that the hostile bishops had been guilty of schism. The bishops of Liguria and Aemilia, headed by the archbishop of Milan, and those of Istria and Venice, headed by Paulinus of Aquileia, also withheld their fellowship; but Narses resisted the appeals of Pelagius, who would have invoked the secular arm. Childebert, king of the Franks, also refused to interfere. Pelagius died on the 4th of March 561, and was succeeded by John III.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)