(May 896–Aug. 897)
Nothing is known of his background except that he was a Roman by birth, son of a presbyter named John, and was consecrated bishop of Anagni by Formosus, whose implacable foe he nevertheless became. Although originally loyal to the German emperor Arnulf (896–9), crowned by Formosus on 22 Feb. 896, he switched his allegiance to Lambert of Spoleto (d. 898), whom Formosus had crowned as co-emperor with his father Guido III (d. 894) in 892, when after Arnulf's paralysis and return to Germany Lambert emerged as ruler of Italy. The sole important event of his reign which has been recorded is the macabre three-day ‘cadaver synod’ over which he presided in Jan. 897. The suggestion that it was instigated in part by Lambert and his mother Ageltrude, resentful against Formosus for having crowned Arnulf, is now generally dismissed: there was sufficient motive in the bitter personal animosity which he and a powerful faction of Romans nourished against the dead pontiff, and also in Stephen's quest for legitimacy. At this mock trial Formosus' disinterred corpse, clad in full papal vestments and propped up on a throne, was solemnly arraigned on charges of perjury, violating the canons prohibiting the translation of bishops, and coveting the papacy. A deacon stood by and answered for him. Formosus was found guilty, and all his acts were declared null and void, including his ordinations; his body was finally flung into the Tiber. While Stephen's participation in this gruesome affair can only be explained by near-hysterical hatred, it is evident that he personally profited by the nullification of Formosus' acts since the resulting cancellation of his own consecration as bishop of Anagni swept away any objections that might be raised, under the canon law of the time, to his elevation to the papacy.
In the following months Stephen was active in requiring clergy ordained by Formosus to produce letters renouncing their orders as invalid. His appalling conduct, however, did not long remain unpunished. A few months later there was a popular reaction, and the outraged supporters of Formosus, encouraged by reports of miracles worked by his humiliated corpse, perhaps also interpreting the sudden collapse of the Lateran basilica as a divine judgement, rose in rebellion, deposed Stephen, stripped him of his papal insignia, and threw him into gaol, where he was shortly afterwards strangled.
JW i. 439 f., ii. 705LP ii. 229E. Dümmler, Auxilius und Vulgarius (Leipzig, 1866)J. Duhr, ‘Le Concile de Ravenne en 898’, RSR22 (1932), esp. 576–8Seppelt ii. 341–3, 346, 349DHGE xv. 1196 f. (A. Dumas)EThC 141 (S. Scholz)Levillain iii. 1459–60 (K. Herbers)NCE xiii. 520 (P. J. Mullins)