In January 897, the Roman Catholic Church witnessed one of the most grotesque spectacles in ecclesiastical history: the Synodus Horrenda, or Cadaver Synod. Pope Stephen VI, driven by political factionalism during the turbulent disintegration of the Carolingian Empire, ordered the body of Pope Formosus to be disinterred seven months after his death. Formosus's decomposing corpse was dressed in full papal robes, seated upon a throne in the Basilica of St.
John Lateran, and appointed a young deacon to speak on its behalf. Stephen VI personally screamed accusations at the corpse, charging Formosus with perjury, violating canon law by acceding to the papacy while already serving as bishop of another diocese, and unlawfully serving as pope. Unsurprisingly, the deceased pope was found guilty on all charges.
The court voided all of Formosus's papal acts and ordinations. As punishment, executioners stripped the body of its sacred vestments, severed the three fingers from its right hand used for papal blessings, and dragged the corpse through the streets of Rome before casting it into the Tiber River. The bizarre trial backfired catastrophically for Stephen VI; public outrage over the desecration incited a riot, leading to Stephen's imprisonment and death by strangulation later that same year.