Date of birth unknown; died 3 March, 561, was a Roman of noble family; his father, John, seems to have been vicar of one of the two civil "dioceses", or districts, into which Italy was then divided. We first meet with him at Constantinople, in the company of Agapitus I, who, just before his death in that city, appointed Pelagius apocrisarius or nuncio of the Roman Church (536). When, through the intrigues of the Empress Theodora, ever scheming for the advancement of the Monophysite heresy, Silverius, the successor of Agapitus in the See of Rome, had been forcibly deposed and banished from Italy by the Greek general Belisarius, the Emperor Justinian issued strict orders that Silverius should be recalled to Rome, and decreed that, if proved innocent, he should be reinstated. If we are to believe Liberatus, an historian opposed to the Fifth General Council, and hence to Popes Vigilius and Pelagius, the latter was prevailed upon by the empress to travel post haste in order to prevent if possible Silverius's return to Italy. In this mission, however, he failed. Nevertheless, the empress accomplished her will, which resulted in the death of Silverius and the accession of Vigilius, of whom she hoped to make a tool. Pelagius meanwhile acquired great influence with Justinian. He selected the orthodox Paul for the See of Alexandria (540), and had to depose him, and choose a successor two years later (542).

The following year, after having brought about the condemnation of Origen, he returned to Rome. After Justinian published (about 544) his decree on the "Three Chapters" (i.e. brief statements of anathema upon Theodore of Mopsuestia and his writings, upon Theodoret of Cyrus and his writings, against St. Cyril of Alexandria and the Council of Ephesus, and upon the letter written by Ibas of Edessa to Maris, Bishop of Hardaschir in Persia), we find Pelagius writing to Fernandus for his opinion on it, and when Vigilius went to Constantinople (Nov., 545) in obedience to the emperor's orders, he remained as his representative in Rome. The times were hard, for Totila, King of the Goths, had begun to blockade the city. The deacon poured out his private fortune for the benefit of the famine-stricken people, and endeavoured to induce the Gothic king to grant a truce. Though he failed, he afterwards induced Totila to spare the lives of the people when he became master of Rome in Dec., 546. That prince conceived so great an admiration for the Roman deacon that he sent him to Constantinople in order to arrange a peace with Justinian, but the emperor sent him back to say that his general Belisarius was in command in Italy, and that he would decide all questions of peace or war.

Once more the energetic deacon returned to Constantinople, this time to support Vigilius, who was being shamefully treated by the emperor, with a view of making him do his will in the matter of the Three Chapters. Encouraged by Pelagius, Vigilius began to offer a stout resistance to Justinian (551) and issued his first "Constitutum" (May, 553). But in June, after the Fifth General Council of Constantinople, which had condemned the Three Chapters, was over and Pelagius and other supporters of the pope had been thrown in to prison, the unfortunate Vigilius gave way, and in his second "Constitutum" (Feb., 554) confirmed the decrees of the Council. Pelagius did not submit at once, but wrote against the opponents of the Three Chapters and blamed the subservience of his superior. At length however he rallied to the pope's side, either because he saw that opposition to him was endangering the unity of the Church, or because, as his adversaries said, he wished to regain Justinian's favour, and by it to succeed Vigilius as pope. It is certain that he did re-enter into the emperor's good graces, shortly before he left Constantinople with the pope, about the beginning of 555. Vigilius died at Syracuse during his return journey (7 June, 555), but it was not till the next year that Pelagius was elected his successor, and consecrated (16 April, 556).

He had no little difficulty in procuring bishops to consecrate him, for there was great opposition to him on account of his change of front regarding the condemnation of the Three Chapters. Some of his enemies even accused him of being responsible for the death of his predecessor. With a view to lessen the ill-feeling against him, he went with the "patrician", Narses, to St. Peter's, and, holding the Gospels and "the Cross of Christ" above his head, he solemnly averred that he had wrought no harm to Vigilius. Then, indirectly to assert the purity of his conduct with reference to his accession to the papacy, he proceeded to denounce simony. His principal aims during his five years' pontificate were to overcome oposition, if not now so much to himself, at any rate to the Fifth General Council, in the West; and to make good the material damage to the Church's property in Italy, brought about by the campaigns between the Greeks and the Goths. Of his personal worth the Romans were again soon convinced, when they saw him use his wealth for their advantage, in the same generous manner as he had done when Totila's blockade had reduced them to the last extremity; as, for example, when they saw him repairing and refurnishing the churches, and reorganizing for the benefit of the poor the possessions and revenues of the Church which the Gothic war, and the long absence of the popes from Rome, had thrown into great confusion.

But Pelagius was not so successful in extinguishing in Italy the schism which the condemnation of the Three Chapters had excited in the West, as he was in winning the confidence of the Romans. The vacillation of Vigilius, and his submission to the will of Justinian, the persecution to which he had been exposed, and the final adhesion of Pelagius himself to his predecessor's decree confirming the Council of Constantinople, embittered the minds of many of the Westerns against the East. They were too angry at the emperor's conduct to realize that with both Vigilius and Pelagius the whole question was rather one of policy and expediency than of religion. Pelagius did all in his power to convince the bishops of Northern Italy, where the schism had taken the deepest hold, that he accepted the first four General Councils as unreservedly as they did, and that the decrees of the recent Council of Constantinople were in no way in real opposition to those of Chalcedon. He pointed out clearly to them that the differences between the two Councils were only on the surface, and not real, and that even if it was not advisable, under the circumstances, to condemn the writings of Theodoret, Theodore, and Ibas, still, as they were de facto heretical, there could be no harm in officially declaring that they were such. But the feelings of many had been so aroused that it was impossible to get them to listen to reason. The pope grew impatient, especially when Paulinus, Bishop of Aquileia, had in synod renounced communion with Rome, and excommunicated the great general Narses, the hope of Italy. In several letters he exhorted the "patrician" to use his military power to suppress the schism, and to seize Paulinus. Narses, however, probably on account of the political difficulties with which he was beset, did not move, and it was not till the seventh century that the schism caused in Italy by the condemnation of the Three Chapters was finally healed.

Pelagius, however, in the matter of the Council of Constantinople was more successful in Gaul than in Italy. In reply to a request from the Frankish King Childebert, he sent him a profession of faith, in which he proclaimed his entire agreement with the doctrines of Leo I, and trusted that no untruths about himself might cause a schism in Gaul. Further, in response to a request from the same king, and from Sapaudus, Bishop of Arles, he granted the latter the pallium, and constituted him his vicar over all the churches of Gaul, as his predecessors had been in the habit of so honouring the See of Arles. By these means he prevented any schism from arising in Gaul.

Making use of the "Pragmatic Sanction", which Justinian issued in August, 554, to regulate the affairs of Italy, thrown into hopeless disorder by the Gothic war, Pelagius was able to remedy many of the evils which it had caused. Fragments of a number of his letters, which were brought to light by E. Bishop comparatively recently, give us an insight into his extraordinary activity in this direction. They reveal him organizing ecclesiastical tribunals, suppressing abuses among clerics, to which the disorders of the times had given rise, putting the patrimonies of the Church on a new footing, and meanwhile gathering money and clothes for the poor from Gaul and from "distant islands and countries". Before he died his regulations for the management of the ecclesiastical estates had begun to bear fruit, and we read of revenues beginning to come in to him from various quarters. This "Father of the poor and of his country" was buried in St. Peter's the day after his death, in front of the sacristy.

Liber Pontificalis, ed. Duchesne, I (Paris, 1886), Vit. Vigilii et Pelagii; Liberatus, Breviarium, c. xxii etc. in P. L., LXVIII; Victor Tunnensis, Chronicon, ibid.; Procopius, De bello Gothico, ed. Dindorf (Bonn, 1833); or in Latin, Muratori, Rerum Italicarum Scriptores, I, pt. I; Facundus, De defens. trium capit. in P. L., LXVII; the letters of Pelagius in P. L., LXIX; Mon. Germ. Hist.: Epistolæ, iii (Berlin, 1892); Jaffé, Regesta, I (2nd ed., Leipzig, 1888). Modern works: especially Diehl, Justinien (Paris, 1901), 340 etc.; Grisar, Hist. de Rome et des Papes (Paris, 1906), I, pt. II, passim; Hodgkin, Italy and her Invaders, IV, V (London, 1895f). An account of E. Bishop's discovery will be found in Mann, Lives of the Popes in the early Middle Ages, III, 233.

Horace K. Mann.