Answer
The Cadaver Synod was a trial in Rome in 897 where Pope Formosus was posthumously deposed, excommunicated, and stripped of his papal robes. The trial was initiated by Pope Stephen VI, who was motivated by his desire to eliminate the rivalry of Formosus, who had been Pope prior to Stephen. The trial was conducted in a manner that was widely seen as sacrilegious and was condemned by the Catholic Church.