Pope Formosus

Pope Formosus (896) was Pope of the Roman Catholic Church from 6 October 891 to his death. His reign as pope was troubled, marked by power struggles over the Patriarchate of Constantinople, the Kingdom of West Francia, and the Holy Roman Empire.
Papacy.
During his papacy, Formosus also had to side with the Saracens, who were attacking Lazio. On 4 April 896, Formosus died. He was replaced by Boniface VI, whose papacy lasted 15 days.
Trial.
He sided with Arnulf of Carinthia against Lambert of Spoleto. He was accused of perjury and was put on trial. As a result, Formosus's remains were exhumed and put on trial in the Cadaver Synod. He was found guilty and his body was buried many times at a nearby river.