Date of birth unknown; died at Rome, 28 June, 767. He was a brother of Stephen II. They had been educated for the priesthood at the Lateran palace. Stephen entrusted his brother, who approved of the pope’s course in respect to King Pepin, with many important ecclesiastical affairs, among others with the restoration to the Roman States of the cities which had been seized by the Lombard Kings Aistulf and Desiderius; these cities Desiderius promised to give up. While Paul was with his dying brother at the Lateran, a party of the Romans gathered in the house of Archdeacon Theophylact in order to secure the latter’s succession to the papal see.
However, immediately after the burial of Stephen (died 26 April, 757), Paul was elected by a large majority, and received episcopal consecration on the twenty-ninth of May. Paul continued his predecessor’s policy towards the Frankish king, Pepin, and thereby continued the papal supremacy over Rome and the districts of central Italy in opposition to the efforts of the Lombards and the Eastern Empire. Pepin sent a letter to the Roman people, exhorting them to remain steadfast to St. Peter. In the reply sent by the senate and the people of Rome to the Frankish king, the latter was urged to complete the enlargement of the Roman province which he had wrested from the barbarians, and to persevere in the work he had begun. In 758 a daughter was born to Pepin, and the king sent the pope the cloth used at the baptism as a present, renewing in this way the papal sponsorship.
Paul returned thanks and informed Pepin of the hostile action of Desiderius, who had failed to deliver the cities of Imola, Osimo, Ancona, and Bologna to Rome, and had also devastated the Pentapolis on his expedition against the rebellious Dukes of Spoleto and Benevento. The two duchies were conquered and annexed by Desiderius (758). At Benevento Desiderius had a conference with the Greek ambassador Georgios, and agreed on a mutual alliance of Byzantines and Lombards in central Italy. On his way home Desiderius came to Rome, and when the pope demanded the return of the aforesaid cities, he refused to comply. He promised to give back Imola, but on condition that the pope should persuade Pepin to send back the Lombard hostages whom the Frankish king had carried off, some time before, at the time of his second victory over the Lombard King Aistulf. If Paul would not do this, Desiderius threatened to go to war with him.
The pope was in great straits. He found it difficult even to get the Frankish king informed of his position. He gave two letters to Bishop George of Ostia and the Roman priest Stephen, his ambassadors to Pepin, who made the journey with the Frankish messenger Ruodpertus. In the one letter that was to secure the envoys a safe passage through Lombard territory, he agreed to the demands of Desiderius and begged Pepin to accede to the wishes of the Lombards by making a treaty of peace and returning the hostages. At the same time the envoys were to give the Frankish king a second secret letter, in which the pope communicated to him the latest occurrences, informed him of the agreement of Desiderius with the Byzantines for the conquest of Ravenna, and implored Pepin to come to the aid of the pope, to punish the Lombard king, and to force him to yield the towns retained by him.
Towards the close of 759 another envoy was sent to Pepin. Early in 760 two Frankish envoys, Bishop Remidius of Rouen, brother to Pepin, and Duke Antschar, came to Desiderius, who promised to return its patrimony to the Roman Church in April, and also to yield the towns demanded by the pope. But he again refused to carry out his promises, dallied, and even forced his way into Roman territory. Once more Paul implored the Frankish king’s help. The position of affairs was made even more threatening by Byzantine action. Georgios had gone from southern Italy to the court of Pepin and had here won over a papal envoy, Marinus. With all his efforts Georgios could not move Pepin. In 760 a report spread through Italy that a large Byzantine fleet was under sail for Rome and the Frankish kingdom.
Later it was reported that the Byzantines intended to send an army to Rome and Ravenna. The Archbishop Sergius of Ravenna received a letter from the Byzantine emperor, in which the latter sought to obtain the voluntary submission of the inhabitants of Ravenna. The same attempt was also made in Venice. Sergius sent the letter of the emperor to the pope, and the pope notified Pepin. In case of a war with the Eastern Empire it was important to make sure of the support of the Lombards, consequently Pepin desired to come to an agreement with Desiderius. Thereupon the Lombard king showed more complaisance in the question of the Roman patrimony included in the Lombard territory, and when he visited Rome in 765, the boundary disputes between him and the pope were arranged.
The Frankish king now directed Desiderius to aid the pope in recovering the Roman patrimony in the regions in southern Italy under Byzantine rule, and to support the ecclesiastical rights of the pope against the bishops of these districts. Paul’s opposition to the schemes of the Emperor Constantine Copronymus had no real political basis. The pope’s aim was to defend ecclesiastical orthodoxy regarding the doctrine of the Trinity and the veneration of images against the Eastern emperor. Paul repeatedly dispatched legates and letters in regard to the veneration of images to the emperor at Byzantium. Constantine sent envoys to western Europe who in coming to King Pepin did not disguise their intention to negotiate with him concerning dogmatic questions, also about the submission of the Exarchate of Ravenna to Byzantine suzerainty.
Papal legates also came to Pepin in regard to these matters. On their return the legates were able to reassure the pope as to the views of the Frankish ruler, who kept two of the papal envoys, Bishop George and the priest Peter, near him. In 767 a Frankish synod was held at Gentilly, near Paris, at which the Church doctrines concerning the Trinity and the veneration of images were maintained. Paul showed great activity and zeal in encouraging religious life at Rome. He turned his paternal home into a monastery, and near it built the church of San Silvestro in Capite. The founding of this church led to his holding a synod at Rome in 761. To this church and other churches of Rome, Paul transferred the bones of numerous martyrs from the decayed sanctuaries in the catacombs devastated by the Lombards in 756.
He transferred the relics of St. Petronilla from the catacomb of St. Domitilla to a chapel in St. Peter’s erected by his predecessor for this purpose. The legend of St. Petronilla caused her at that era to be regarded as a daughter of St. Peter, and as such she became the special Roman patroness of the Frankish rulers. Paul also built an oratory of the Blessed Virgin in St. Peter’s, and a church in honour of the Apostles on the Via Sacra beyond the Roman Forum. He died near the church of San Paolo fuori le mura, where he had gone during the heat of summer. He was buried in this church, but after three months his body was transferred to St. Peter’s. The “Liber Pontificalis” also praises the Christian charity and benevolence of the pope which he united with firmness. Paul is venerated as a saint. His feast is celebrated on the twenty-eighth of June.