Whose body did Pope Stephen VI have exhumed, tried, de-fingered and thrown in the river?
Pope Stephen VI (who was Pope from May 896 to his death in 897) is chiefly remembered in connection with his conduct towards the remains of Pope Formosus, his predecessor. The rotting corpse of Formosus was exhumed and put on trial in the so-called Cadaver Synod (or Synodus Horrenda) in January 897. Pope Stephen's great dislike for his predecessor probably helped to precipitate his extraordinary actions. Also, based on political reasons and the desires of Roman aristocrats who were fighting with rulers of Naples, Pope Stephen was convinced to have the body of his predecessor exhumed.
When the corpse was put on a throne, a deacon was appointed to answer for the deceased pontiff. The corpse of Pope Formosus was then found guilty. It was stripped of its sacred vestments, deprived of three fingers on its right hand (the blessing fingers), clad in the garb of a layman and quickly buried. It was finally thrown in the Tiber. All ordinations performed by Pope Formosus were annulled.
Concerning Pope Stephen VI, an insurrection removed him from office. Deprived of papal insignia, he was imprisoned and strangled. However, his followers found another leader in Pope Sergius III. Twelve years of blood, intrigue, and terror followed.