(10 May 946–Dec. 955)
The successor of Marinus II, he owed his promotion to Alberic II (c. 905–54), prince of Rome and from 932 to 954 its all-powerful ruler. Except that he was a Roman by birth, nothing is known of his origins or previous career. While the other popes appointed by Alberic were largely restricted to ecclesiastical functions, he was able, at any rate at the beginning of his reign, to exercise considerable initiative in the political field outside Italy; his name in full appeared on coins in contrast to the simple monogram of Alberic's earlier nominees.
He cooperated fully with Alberic in fostering monastic reform, confirming the special status of Cluny, near Mâcon, and arranging, c.950, for monks to come from Gorze (diocese of Metz) to restore discipline in the abbey attached to S. Paolo fuori le Mura. Farther afield, his legate, Bishop Marinus, was dispatched in spring 948 to the court of King Otto I of Germany (936–73: in 962 emperor), and then presided with Otto and Louis IV d'Outremer of France (936–54) over the important synod of Ingelheim (7 June), which not only settled the contested succession to the see of Reims in favour of Artaud, King Louis's candidate, but attempted to remedy the troubled situation in the kingdom of France by ordering Louis's rebellious vassal, Hugh the Great, to make his submission on pain of excommunication. Agapitus ratified these decisions at a Roman synod early in 949. In a bull dated 2 Jan. 948 he had extended the jurisdiction of the metropolitan of Hamburg–Bremen over Denmark and other northern countries. He worked closely with, and admired, Otto, and when the Saxon king crossed the Alps in autumn 951, assumed the royal power at Pavia, and sent envoys to Rome (significantly to the pope and not the prince) to negotiate for the imperial crown, Agapitus would gladly have offered it to him had he been free to do so. He was obliged to refuse, however, since Alberic, who had no wish to see Rome dominated by a foreign emperor, was firmly opposed to the project. In spite of this Agapitus continued his active support for Otto, granting him broad jurisdiction over monasteries, in 954 permitting his brother Bruno, archbishop of Cologne (953–65), to wear the pallium at will, endorsing the king's plan to transform the monastery of St Maurice he had founded at Magdeburg in 937 into a metropolitan see with oversight of the mission to the Slavs, and (as emerges from a letter of protest addressed to the pope in 955 by William, archbishop of Mainz) giving him authority to establish archbishoprics and bishoprics and define ecclesiastical boundaries as he thought fit. He thus played a definite role in the process which was to lead to the imperial restoration in 962.
Notwithstanding his energy and independence, the weakness of Agapitus' position was revealed when Alberic lay dying. Anxious that all power in Rome, spiritual as well as temporal, should be concentrated in his family, the prince assembled the nobility and clergy, with the pope, in St Peter's and made them swear that after Agapitus' death they would elect his bastard son Octavian, who was to succeed him as prince, as supreme pontiff as well. Agapitus was thus forced to be a party to this profoundly uncanonical undertaking. Alberic died on 31 Aug. 954, being succeeded by Octavian as temporal ruler, and Agapitus a little more than a year later; he was buried behind the apse of St John Lateran.