(Sept. 885–14 Sept. 891)
A Roman of aristocratic family who entered the Lateran under Hadrian II to be educated by his relative, the papal librarian, he was cardinal priest of SS. Quattro Coronati when he was elected by acclamation by the clergy and leading laity. Emperor Charles the Fat (881–8), annoyed because he had not been consulted about the election and preferring a creature of his own, sent his chancellor Liutward, bishop of Vercelli, to Rome to have him deposed. Stephen, however, was able to satisfy Liutward that he had been the unanimous choice of the electors and that the resident imperial envoy had even assisted him to take possession of the papal palace. The matter was dropped.
After carrying out a thorough purge and reorganization of the Lateran, Stephen invited Charles to come to Italy to fulfil his duties as protector of the church; he was threatened by party strife in Rome and by increasing Saracen raids. Charles made the journey in spring 886, but was almost at once obliged to recross the Alps to deal with trouble in France. The help which Stephen urgently needed never came. In Nov. next year Charles was deposed, and when he died on 13 Jan. 888 the empire of Charlemagne finally disintegrated. Desperate for a protector, Stephen first (890) summoned Arnulf (c. 850–99), Charles's nephew, who had been proclaimed king of the East Franks in 887, to rescue Italy from the devastations of ‘pagans and evil Christians’. As Arnulf, occupied with other tasks, could do nothing for the moment, Stephen made a drastic change of papal policy and drew closer to Guido III, duke of Spoleto (d. 894), who had seized the throne of Italy in 889; he adopted him as son and eventually (21 Feb. 891) was induced, probably by fear, to crown him Holy Roman emperor and his wife Ageltrude as empress in St Peter's. But while Guido entered into the customary pact guaranteeing the privileges of the Roman church, he had effectively secured the supremacy over the papal state for which he had striven.
Although his reign was a mainly political one, Stephen forcefully asserted his authority over bishops in France and Germany. Like his immediate predecessors, he maintained friendly relations with Constantinople, all the more closely as he needed military aid from it. Although he had to reprove Emperor Basil I (867–86) for hostile references to Marinus I, whose election he continued to contest, he was on good terms with him personally, asking him to send warships to defend the coasts of the papal state against Saracen attacks and cooperating with Byzantium against the Muslim peril. When Basil was succeeded by Leo VI (886–912) and the great patriarch Photius (858–67; 878–86) had to abdicate, Stephen seems to have acknowledged the new patriarch, Stephen I (the emperor's brother). Although in Francia he succeeded in calling both the bishop of Bordeaux and the archbishop of Lyon to account for failing to observe the canons, he had less success elsewhere.
The victim of intrigues he did not understand, Stephen missed a great opportunity in Moravia, where Archbishop Methodius, apostle of the Slavs and promoter of the Slavonic liturgy, had died on 6 Apr. 885. He had designated his disciple Goradz as his successor, but influenced by German clergy the pope summoned Goradz to Rome, forbade the Slavonic liturgy while permitting preaching in Slavonic, and appointed Bishop Wiching of Nitra, Methodius' suffragan, as administrator of the metropolitan see. The Moravian church was to be organized according to the wishes of the German hierarchy. As a result the small group of Methodius' disciples were unable to maintain themselves and escaped to Bulgaria, where they reverted to the Byzantine rite in the Slavonic tongue. The foundations were thus laid for a Slav-speaking church which would eventually spread to include Russia, but which was alien from Rome and maintained close ties with Orthodoxy.