The Sword of Peter

By Thomas V. Mirus ( bio - articles - email ) | Jul 20, 2026 | In Lives of the Popes

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This installment of Lives of the Popes covers two popes of the early 5^th century, the first of whom passed on multiple complicated situations for his successor to resolve.

41—St. Zosimus (417-18)

St. Zosimus was Greek, possibly with a Jewish father. Most of what we know of him involves his responses to various appeals, by which he was perhaps too easily influenced. His decisions in multiple cases brought about unnecessary complication and controversy.

Soon after his election Pope Zosimus was convinced to intervene in a conflict of jurisdiction between some bishops in Gaul; his intervention in favor of the local supremacy of the bishop of Arles exacerbated a dispute which would not be fully resolved until Pope St. Leo the Great.

In another case, the African priest Apiarius of Sicca appealed to the pope after he was excommunicated by his bishop. This immediate appeal to Rome was contrary to the established procedure of ecclesiastical appeals in Africa, but Zosimus accepted Apiarius’s appeal and sent legates to Africa to investigate. In his written response, Zosimus cited a canon which he mistakenly thought was from the Council of Nicaea, but which was only from the council of Sardica, a council not binding in Africa. The pope’s handling of Apiarius’s appeal again resulted in controversy going beyond his own reign.

Finally, Pope St. Zosimus intervened in the Pelagian controversy, first uncertainly and then firmly. First, he gave consideration to the appeal of Pelagius’s chief disciple, Caelestius, who had been condemned by Pope St. Innocent I. At a meeting in the church of San Clemente, Caelestius convinced Pope Zosimus that the condemnation may have been hasty. Pelagius himself, seeking to clear his name after having been excommunicated by the previous pope, also sent St. Zosimus a confession of faith and a treatise on free will. These writings were examined at a synod in Rome which found them to be orthodox, and Zosimus wrote to the African bishops accusing them of hastiness in having condemned both Caelestius and Pelagius.

The Africans responded in a synod at Carthage, insisting that the pope had been deceived by the Pelagian heretics about their true beliefs, and that the prior decision by Pope St. Innocent must be retained. Pope Zosimus then backtracked, saying that he had not meant to settle anything finally without consulting the African bishops, while also reminding them of his authority to make the final decision. The Africans also got Emperor Honorius to condemn the Pelagians, and finally, in 418, Zosimus conceded the point and promulgated his Tractoria condemning the Pelagians as heretics. In doing so, St. Prosper of Aquitaine later wrote, Pope Zosimus “placed the sword of Peter in the hands of all the bishops to cut off the heretics from our communion.”

Whether because of his divisive ruling style or for other reasons, St. Zosimus’s final months saw the emergence of factions which would cause serious problems in the next election.

42—St. Boniface I (418-22)

St. Boniface, a former counselor of Pope St. Innocent I, was a married man, but his wife died before he was elected Bishop of Rome. His accession to the Petrine Throne did not come easily or peacefully, and in fact the circumstances surrounding his election are some of the most interesting information we have about this pope. Thus I will quote at length the Catholic Encylopedia’s account of these dramatic events:

At the death of Pope Zosimus, the Roman Church entered into the fifth of the schisms, resulting from double papal elections, which so disturbed her peace during the early centuries. Just after Zosimus’s obsequies, 27 December, 418, a faction of the Roman clergy consisting principally of deacons seized the Lateran basilica and elected as pope the Archdeacon Eulalius. The higher clergy tried to enter, but were violently repulsed by a mob of adherents of the Eulalian party. On the following day they met in the church of Theodora and elected as pope, much against his will, the aged Boniface, a priest highly esteemed for his charity, learning, and good character.

On Sunday, 29 December, both were consecrated, Boniface in the Basilica of St. Marcellus, supported by nine provincial bishops and some seventy priests; Eulalius in the Lateran basilica in the presence of the deacons, a few priests and the Bishop of Ostia, who was summoned from his sickbed to assist at the ordination. Each claimant proceeded to act as pope, and Rome was thrown into tumultuous confusion by the clash of the rival factions.

The Prefect of Rome, Symmachus, hostile to Boniface, reported the trouble to Emperor Honorius at Ravenna, and secured the imperial confirmation of Eulalius’s election. Boniface was expelled from the city. His adherents, however, secured a hearing from the emperor, who called a synod of Italian bishops at Ravenna to meet the rival popes and discuss the situation (February, March, 419). Unable to reach a decision, the synod made a few practical provisions pending a general council of Italian, Gaulish, and African bishops to be convened in May to settle the difficulty. It ordered both claimants to leave Rome until a decision was reached and forbade return under penalty of condemnation.

As Easter, 30 March, was approaching, Achilleus, Bishop of Spoleto, was deputed to conduct the paschal services in the vacant Roman See. Boniface was sent, it seems, to the cemetery of St. Felicitas on the Via Salaria, and Eulalius to Antium. On 18 March, Eulalius boldly returned to Rome, gathered his partisans, stirred up strife anew, and spurning the prefect’s orders to leave the city, seized the Lateran basilica on Holy Saturday (29 March), determined to preside at the paschal ceremonies. The imperial troops were required to dispossess him and make it possible for Achilleus to conduct the services.

The emperor was deeply indignant at these proceedings and refusing to consider again the claims of Eulalius, recognized Boniface as legitimate pope (3 April, 418). The latter re-entered Rome 10 April and was acclaimed by the people. Eulalius was made bishop either of Nepi in Tuscany or of some Campanian see, according to the conflicting data of the sources of the “Liber Pontificalis”. The schism had lasted fifteen weeks.

Early in 420, the pope’s critical illness encouraged the partisans of Eulalius to make another effort. On his recovery Boniface requested the emperor (1 July, 420) to make some provision against possible renewal of the schism in the event of his death. Honorius enacted a law providing that, in contested Papal elections, neither claimant should be recognized and a new election should be held.

St. Boniface supported St. Augustine in the fight against Pelagianism, forwarding to Augustine two letters the Pelagians had written against him. Augustine dedicated his refutation of these letters to Pope Boniface.

But much of this pope’s rule was focused on matters of discipline and jurisdiction, including problems passed on from his predecessor, St. Zosimus. Zosimus had controversially granted an excessive primacy to the Bishop of Arles over the other bishops of Gaul, and St. Boniface now diminished that primacy over the region while restoring the prerogatives of the provincial bishops.

Likewise, Boniface inherited the controversy with the African bishops over Apiarius, but while these bishops were annoyed because Zosimus had mistakenly cited a canon from a local council as a canon of Nicaea, they humbly agreed to obey it anyway out of respect for Rome.

Like his predecessors, St. Boniface continued to maintain papal jurisdiction over the province of Illyricum against Eastern encroachment. Emperor Theodosius II had made a law granting jurisdiction to Constantinople, but Boniface convinced him not to enforce it.

In two letters responding to the dispute over Illyricum, St. Boniface expressed a doctrine of papal primacy as inherent to the divine constitution of the Church, rather than established by positive canon law. In his study The Papacy, Erick Ybarra paraphrases St. Boniface’s view as follows:

The See of Constantinople was usurping prerogatives that did not belong to her. Three churches of the oikumene [the one universal Christian society] alone were canonically set apart with such prerogatives: Rome, Alexandra, and Antioch. The nature of their primacies required a certain “obedience” in the “bond of love” for the sake of ecclesiastical order and unity. Though the Council of Nicaea (325) speaks of prerogatives to be assigned to the sees of Alexandria and Antioch, nothing was assigned to See of Rome. The council and the Fathers understood that nothing could be added to the prerogatives of the Roman See because it had been universally known that “all” had been invested in St. Peter by the word of the Lord. Consequently, St. Peter’s See (Rome) is the head of all the churches, and the see to which all must submit in obedience for the sake of love and discipline. The office of Peter is not a canonically created organ of the Church, but stretches back to the Church’s “birth” and is the “source” of ecclesiastical unity for “all the Churches.” The canons which speak to Roman primacy are therefore reflective of an already existing institution by divine or apostolic right and are not causative or a novel introduction ex nihilo or from canonical origin.