In 896 Pope Stephen VI put the corpse of his predecessor, Pope Formosus, on trial in a Church synod in Rome, known since as the Cadaver Synod. The pontificate and the ordinations of Formosus were annulled and he was reburied in a pilgrims' cemetery from which his body was quickly removed and thrown into the Tiber. It still is generally assumed that Formosus was tried as revenge for his having betrayed Lambert of Spoleto by inviting Arnulf of Carinthia to become emperor, and that Pope Stephen VI was carrying out the wishes of Lambert and his mother. This dissertation, by examining the entire career of Formosus as well as the manuscript evidence for the Cadaver Synod and the 898 Synod of Ravenna, which overturned it, will present a new view of what happened in this neglected period of European history. In so doing, it has reached very different conclusions about the trial and its purpose.