View the following scene:  Europe, the late ninth century. Rome is a game piece between the Papacy and the Holy Roman Empire, largely controlled by small-time warlords, and wanted by pretty much everyone who was anybody in central Italy, for some reason, even though the place had, by papal admission, gone to shit. Everyone, including Saracen pirates, had sacked the city, stolen all the pope’s stuff several times over, and generally made a mess of things.
After a few years of mediocrity, Pope Formosus dies. Pope Boniface VI becomes pope, dies. Pope Stephen VI becomes pope, promptly conducts the Cadaver Synod. Stephen had Formosus exhumed, tried in Saint John Lateran (Stephen and his pals placed Formosus on a throne and questioned him repeatedly about certain acts of which he was accused, and getting no reply other than a vague musty smell, presumed the late pontiff’s corpse was remaining silent because it was guilty of all charges), and found guilty of not being worthy of the office of the papacy, and punished accordingly: every act he passed was annulled, his papal vestments and rings (by this point, he was a tad bit moldy) were stripped from his body, three fingers on his right hand (those used for consecrating) were chopped off, and then he was tossed into the Tiber. However, a monk wandering along the Tiber, noticed his body, and remembering that one time Formosus gave him a sandwich, secretly buried it. Somehow, the washed up, eight-fingered ex-pope’s corpse became the source of rumors relating to its miraculous healing abilities (not, unfortunately for Formosus, on his own departed form, but rather on folks who touched it or asked nicely to be cured of an ailment in its presence), and Stephen VI promptly found himself with angry mobs pissed that he had exhumed, tried, defrocked, and unhanded their favorite pope. Shortly after the mob arose, Stephen was imprisoned and strangled by his political enemies (of which he had quite a few). The next few popes tried to gloss over that one time Stephen went out back with a shovel and started digging up former pontiffs, and so they passed laws that forbade the exhumation, trial, and sentencing of the deceased, because, apparently, it hadn’t been clear enough tosome people that you probably shouldn’t go around digging up the bodies of your political enemies and putting them on trial(and then yell at them when they didn’t answer your questions). There was also the matter of the bishops Formosus had created, who, under Stephen’s orders, needed to be re-consecrated as bishops due to Formosus not being pope enough for the job, one of those bishops was, awkwardly, Stephen VI. The papacy largely just shuffled papers around until everything looked legitimate, and did its best to pretend that nothing weird at all was going. So, Formosus rested as serenely as a seriously beaten corpse could rest in the crypt of Saint Peter’s for about a decade. But then Formosus was reexhumed by Pope Sergius III, whom, after teabagging Formosus and saying “No, you’re a douche,” recondemned Formosus for being a sub-par pontiff, reinvalidated all of his rulings, and then according to some rumors, ordered the corpse beheaded (because chopping off a few fingers and tossing the rest into the Tiber hadn’t been enough, apparently), before dropping dead dying himself and leaving it to his ecclesiastical successors to not so secretly bury Formosus in St. Peter’s, and just try to put the whole thing behind them without too much therapy or paperwork. Sergius III’s trial of Formosus was largely viewed as having been a ‘political’ matter, and not one questioning the faith of Formosus, so the Church ruled once and for all that the rulings made by Formosus were valid, and everyone should really stop digging him up to yell at him. Political matters in the early middle ages, you see, were those that involved digging up or otherwise utilizing a corpse in order to make everyone else just shake their head and mutter under their breath as they wonder just where they went wrong.