The Cadaver Synod (also called the Cadaver Trial; Latin: Synodus Horrenda) is the name commonly given to the ecclesiastical trial of Pope Formosus, who had been dead for about seven months, in the Basilica of St. John Lateran in Rome during January 897. The trial was conducted by Pope Stephen VI, the successor to Formosus' successor, Pope Boniface VI. Stephen had Formosus' corpse exhumed and brought to the papal court for judgment. He accused Formosus of perjury, of having acceded to the papacy illegally, and ruling over more than one place at a time. At the end of the trial, Formosus was pronounced guilty and his papacy retroactively declared null.
The Cadaver Synod and related events took place during a period of political instability in Italy. This period, which lasted from the middle of the 9th century to the middle of the 10th century, was marked by a rapid succession of pontiffs. Between 872 and 965, two dozen popes were appointed, and between 896 and 904 there was a new pope every year. Often, these brief papal reigns were the result of the political machinations of local Roman factions, about which few sources survive.
Formosus became bishop of Porto-Santa Rufina in 864 during the pontificate of Pope Nicholas I. In 866 he was sent as a legate to Bulgaria, and was so successful in this position that the Bulgarian ruler Boris I asked the pope to appoint him archbishop of Bulgaria. Nicholas refused to give permission, because the fifteenth canon of the Second Council of Nicaea forbade a bishop from administering more than one see — "a law that was supposed to prevent bishops from building up their own little fiefdoms." He also travelled to Constantinople, and the Carolingian court, where he met Arnulf of Carinthia, a Frankish Carolingian king who aspired to the throne of Italy.
In 875, shortly after Charles the Bald's imperial coronation, Formosus fled Rome in fear of then-pope John VIII. A few months later in 876, at a synod in Santa Maria Rotunda, John VIII issued a series of accusations against Formosus and some of his associates. He asserted that Formosus had corrupted the mind of the Bulgarians "so that, so long as [Formosus] was alive, [they] would not accept any other bishop from the apostolic see," that he and his fellow conspirators had attempted to usurp the papacy from John, and finally that he had deserted his see in Porto and was conspiring "against the salvation of the state[verification needed] and of our beloved Charles [the Bald]." Formosus and his associates were excommunicated.
In 879, at another council held at Troyes, John may have confirmed the excommunications. He also legislated more generally against those who "plunder" ecclesiastical goods. According to the tenth-century author Auxilius of Naples, Formosus was also present at this council. Auxilius says he begged the bishops for their forgiveness, and in return for removal of the excommunication, swore an oath to remain a layman for the rest of his life, to never again enter Rome, and to make no attempts to resume his former see at Porto. This story is dubious: another description of the synod does not mention Formosus's presence and says instead that John confirmed his excommunication.
After the death of John VIII in December 882, Formosus' troubles ended. He resumed his bishopric at Porto, where he remained until elected pope on 6 October 891. Yet this earlier quarrel with John VIII formed the basis of the accusations made at the Cadaver Synod. According to the tenth-century historian Liutprand of Cremona, Stephen VI asked Formosus' corpse why he "usurped the universal Roman See in such a spirit of ambition" after the death of John VIII, echoing John VIII's own assertion that Formosus had tried to seize the papal throne while he was alive. Two further accusations were also made against Formosus at the Cadaver Synod: that he had committed perjury and that he had attempted to exercise the office of bishop as a layman. These are related to the oath Formosus is said to have sworn before the council at Troyes in 878.
The Cadaver Synod is generally presumed to have been politically motivated. Formosus crowned Lambert of Spoleto co-ruler of the Holy Roman Empire in 892; Lambert's father, Guy III of Spoleto, had earlier been crowned by John VIII. In 893 Formosus, apparently nervous about Guy's aggression, invited the Carolingian Arnulf of Carinthia to invade Italy and receive the imperial crown. Arnulf's invasion failed, and Guy III died shortly afterwards. Yet Formosus renewed his invitation to Arnulf in 895, and early the next year Arnulf crossed the Alps and entered Rome, where Formosus crowned him as Holy Roman Emperor. Afterwards the Frankish army departed, and Arnulf and Formosus died within months of each other in 896. Formosus was succeeded by Pope Boniface VI, who himself died two weeks later. Lambert and his mother, the empress Angiltrude, entered Rome around the time that Stephen VI became pope, and the Cadaver Synod was conducted directly afterwards, at the beginning of 897.
The dominant interpretation of these events until the early twentieth century was straightforward: Formosus had always been a pro-Carolingian, and his crowning of Lambert in 892 was coerced. After the death of Arnulf and the collapse of Carolingian authority in Rome, Lambert entered the city and forced Stephen to convene the Cadaver Synod, both to re-assert his claim to the imperial crown and perhaps also to exact posthumous revenge upon Formosus.
This view is now considered obsolete, following the arguments put forth by Joseph Duhr in 1932. Duhr pointed out that Lambert was in attendance at the Ravenna Council of 898, convened under Pope John IX. It was at this proceeding that the decrees of the Cadaver Synod were revoked. According to the written acta of the council, Lambert actively approved of the nullification. If Lambert and Angiltrude had been the architects of Formosus's degradation, Duhr asked, "how [...] was John IX able to submit to the canons which condemned the odious synod for approbation of the emperor [i.e., Lambert] and his bishops? How could John IX have dared to broach the matter [...] before the guilty parties, without even making the least allusion to the emperor's participation?" This position has been accepted by another scholar: Girolamo Arnaldi argued that Formosus did not pursue an exclusively pro-Carolingian policy, and that he even had friendly relations with Lambert as late as 895. Their relations only soured when Lambert's cousin, Guy IV of Spoleto, marched on Benevento and expelled the Byzantines there. Formosus panicked at the aggression and sent emissaries into Bavaria seeking Arnulf's help. Arnaldi argues that it was Guy IV, who had entered Rome along with Lambert and his mother Angiltrude in January 897, who provided the impetus for the synod.
Probably around January 897, Stephen VI ordered that the corpse of his predecessor Formosus be removed from its tomb and brought to the papal court for judgment. With the corpse propped up on a throne, a deacon was appointed to answer for the deceased pontiff.
Formosus was accused of transmigrating sees in violation of canon law, of perjury, and of serving as a bishop while actually a layman. Eventually, the corpse was found guilty. Liutprand of Cremona and other sources say that, after having the corpse stripped of its papal vestments, Stephen then cut off the three fingers of the right hand that it had used in life for blessings, next formally invalidating all of Formosus' acts and ordinations (including his ordination of Stephen VI as bishop of Anagni). The body was finally interred in a graveyard for foreigners, only to be dug up once again, tied to weights, and cast into the Tiber River.
The macabre spectacle turned public opinion in Rome against Stephen. Formosus' body washed up on the banks of the Tiber, and rumor said it had begun to perform miracles. A public uprising deposed and imprisoned Stephen. He was strangled in prison in July or August 897.
In December 897 Pope Theodore II (897) convened a synod that annulled the Cadaver Synod, rehabilitated Formosus, and ordered that his body, which had been recovered from the Tiber, be reburied in Saint Peter's Basilica in pontifical vestments. In 898, John IX (898–900) also nullified the Cadaver Synod, convening one synod in Rome, and another in Ravenna. The two synods which affirmed the findings of Theodore II's synod, ordered the acta of the Cadaver Synod destroyed, excommunicated seven cardinals involved in the Cadaver Synod, and prohibited any future trial of a corpse.
However, Pope Sergius III (904–911), who as bishop had taken part in the Cadaver Synod as a co-judge, overturned the rulings of Theodore II and John IX, reaffirming Formosus's conviction, and had a laudatory epitaph inscribed on the tomb of Stephen VI.
- Damnatio memoriae
- Devil's advocate
- List of excommunicable offences in the Catholic Church
- List of people excommunicated by the Catholic Church
- Posthumous execution
- Pope Boniface VIII
- The Ring and the Book
- For the date cf. Joseph Duhr, "Le concile de Ravenne in 898: la réhabilitation du pape Formose", Recherches de science religieuse 22 (1932), p. 541, note 1.
- Harper, Elizabeth (3 March 2014). "The Cadaver Synod: When a Pope's Corpse Was Put on Trial". Atlas Obscura. Retrieved 13 December 2021.
- Wilkes Jr., Donald E. (31 October 2001). "The Cadaver Synod: Strangest Trial in History". Flagpole Magazine. Athens, Georgia, USA: 8. Retrieved 8 October 2010.
- Alberto Reche Ontillera (20 August 2019). "In 897, the corpse of a pope was exhumed—to be put on trial: Known as the 'Cadaver Synod,' the posthumous trial of Pope Formosus resulted from the chaos of the ninth century as factions battled for control of the church". National Geographic. Retrieved 29 April 2019.
- ELIZABETH HARPER (3 March 2014). "The Cadaver Synod: When a Pope's Corpse Was Put on Trial". Atlas Obscura.
- John VIII, JE 3041, ed. E. L. E. Caspar, MGH Epistolae Karolini Aevi, vol. 5, p. 327.
- John VIII, Epistolae, ed. Caspar, p. 327.
- The council acta do not survive, but the proceedings are described by Hincmar,Annales, entry for 878, ed. in Monumenta Germaniae Historica Scriptores vol. I, p. 507.
- Auxilius, Auxilius, In defensionem sacrae ordinationis papae Formosi, I. 4, ed. Dümmler, Auxilius und Vulgarius (Leipzig, 1866), p. 64.
- Hubert Mordek and Gerhard Schmitz, "Papst Johannes VIII. und das Konzil von Troyes," in Geschichtsschreibung und Geistiges Leben im Mittelalter: Festschrift für Heinz Löwe zum 65. Geburtstag, ed. Karl Hauck and Hubert Mordeck (Cologne, 1978), p. 212, n 22.
- Dümmler, Auxilius und Vulgarius, p. 6, nn. 5 and 6.
- Liutprand, Antapodosis, I.30, ed. in Corpus Christianorum: Continuatio Medievalis, vol 156, p. 23, lines 639-43.
- Council of Ravenna in 898, acta edited by J.D. Mansi,Sacrorum conciliorum, nova, et amplissima collectio, vol. 18, col. 221.
- Williams, George L. 2004. Papal Genealogy: The Families and Descendants of the Popes. McFarland & Company. ISBN 0-7864-2071-5. p. 10.
- Cf., for example, Duchesne, Les premiers temps de l'état pontifical (Paris, 1904), p. 301; and the detailed account in the old Catholic Encyclopedia Pope Formosus
- Joseph Duhr, "La concile de Ravenne in 898: la réhabilitation du pape Formose", Recherches de science religieuse 22 (1932), p. 546.
- Girolamo Arnaldi, "Papa Formoso e gli imperatori della casa di Spoleto", Annali della facoltà di lettere e filosofia di Napoli 1 (1951), p. 85ff. Portions of this view had been argued earlier by G. Fasoli, I re d'Italia (Florence, 1949), 32ff.
- Arnaldi, "Papa Formoso", p. 103.
- "Quo constituto...formosum e sepulcro extrahere atque in sedem Romani...collocare praecepit. Cui et ait: 'Cum Portuensis esses episcopus, cur ambitionis spiritu Romanam universalem usurpasti sedem?" Liutprand, Antapodosis, I.30 (CCCM 156, p. 23, ll. 639-43). Liutprand of Cremona's is perhaps the most convenient account of synod, though many additional details are furnished by the pro-Formosan Auxilius. Cf. Dümmler's edition, Auxilius und Vulgarius (Leipzig, 1866), chs. IV (p. 63ff) and X (p. 70ff) especially.
- Amelia Soth (7 February 2019). "The Cadaver Synod: Putting a Dead Pope on Trial: Why did Pope Stephen VI go to such great lengths to destroy an enemy who was already dead?". CABINET OF CURIOSITIES. JStor. Retrieved 29 August 2020.
- Joseph Cummins (2011). History's Great Untold Stories: Obscure Events of Lasting Importance. Allen & Unwin. ISBN 978-1742665122 – via Google Books.
- Wilkes Jr., Donald E. (31 October 2001). "The Cadaver Synod: Strangest Trial in History". Flagpole. Athens, GA: Pete McCommons. pp. 8–9. Retrieved 29 August 2020 – via Digital Commons @ Georgia Law.
- Williams, 2004, p. 11.
- Cummins, Joseph. 2006. History's great untold stories. pp. 10–19.
- Girolamo Arnaldi, "Papa Formoso e gli imperatori della casa di Spoleto", Annali della facoltà di lettere e filosofia di Napoli 1 (1951), discusses the political circumstances of the synod, and argues that Stephen VI may have convened it at the impetus of Guido IV.
- Robert Browning's lengthy poem, The Ring and the Book, devotes 134 lines to the Cadaver Synod, in the chapter called The Pope.
- Joseph Duhr, "La concile de Ravenne in 898: la réhabilitation du pape Formose", Recherches de science religieuse 22 (1932), pp. 541ff, discusses Ravenna council acta of 898, an important source and political circumstances; argues Lambert could not have been its architect
- Ernst Ludwig Dümmler, Auxilius und Vulgarius (Leipzig, 1866), edits the works of two tenth-century Italian clerics who provide important evidence for the synod, its circumstances and aftermath. Also includes an important historical discussion of the synod in his introduction.
- Peter Llewellyn, Rome in the Dark Ages (London, 1970), narrates the history of Rome at the end of the ninth and the beginning of the tenth centuries. Llewellyn discusses both Formosus and the Cadaver Synod.
- William S. Monroe, "The Cadaver Synod and the End of the Carolingian Empire", Paper given at the Medieval Academy of America Annual Meeting on 27 February 2016
- Michael Edward Moore, "The Attack on Pope Formosus Papal History in an Age of Resentment (875-897)", Ecclesia et Violentia: Violence Against the Church and Violence Within the Church, eds. Michael E. Moore, Jacek Maciejewski and Radoslav Kotecki (Cambridge Scholars Publishing, 2014)
- Démètre Pop, La défense du pape Formose (Paris, 1933), analyzes posthumous defense of Formosus put forth by Auxilius and Vulgarius
- The Complete Works of Liudprand of Cremona, trans. By Paolo Squatriti (Catholic University Press of America, 2007)
- Donald E. Wilkes Jr, The Cadaver Synod: The Strangest Trial in History (2001).
- Frédéric Cathala, Le Synode du Cadavre, Les Indes Savantes, 2012.
- The play Infallibility, which premiered at the 2013 New York International Fringe Festival, features the Cadaver Synod.