Little is known of Theodore's background; he is recorded as being born a Roman, and the son of Photios. His brother Theodosius was also a bishop. Theodore was ordained as a priest by Pope Stephen V. In January 897, Pope Stephen VI held what is known as the Cadaver Synod. Because his predecessor, Formosus, sided with Arnulf of Carinthia rather than Stephen's ally, Lambert of Spoleto, in their struggle for the imperial dignity, Stephen had the corpse of Formosus exhumed and tried for "perjury, violating the canons prohibiting the translation of bishops, and coveting the papacy". The dead pope was found guilty, his body thrown in the Tiber, and all his acts and ordinations were annulled. Supporters of Formosus rebelled and deposed Stephen VI. His successor, Romanus, is generally assumed to have been pro-Formosus, but he too was soon deposed.
Papacy
Theodore II was elected to succeed the deposed Romanus as pope. The exact dates of Theodore II's reign are unknown, but modern sources generally agree that he was pope for twenty days during December 897. Flodoard, a tenth-century French chronicler, only credited Theodore with a twelve-day reign, while in his history of the popes, Alexis-François Artaud de Montor listed Theodore's reign as being twenty days, from 12 February to 3 March 898. Like Romanus, Theodore was a supporter of Formosus. Some historians believe that Romanus had been deposed because he had not acted to restore Formosus' honour quickly enough, though others suggest that he was removed by supporters of Stephen VI. In either case, Theodore immediately threw himself into the task of undoing the Cadaver Synod. He called his own synod, which annulled the rulings set out by Stephen VI. In so doing, he restored the acts and ordinations of Formosus, including the restoration of a large number of clergy and bishops to their offices. Theodore also ordered Formosus' body to be recovered from the harbour of Portus, where it had been secretly buried, and restored to the original grave at Old St. Peter's Basilica. Like Romanus before him, Theodore bestowed a privilege upon the See of Grado, and had a coin minted, bearing the name of Lambert on the obverse, and "Scs. Petrus" and "Thedr." on the reverse. Flodoard cast Theodore in a positive light, describing him as "beloved of the clergy, a friend of peace, temperate, chaste, affable and a great lover of the poor." He died in office, though the cause of his death is unknown. Because of this, some writers, such as, Wendy Reardon) suggest the possibility of foul play. Horace Kinder Mann offers a different suggestion in his papal history, noting that it is possible that popes who were "infirm or even older than their predecessors" might have been elected intentionally. Theodore was buried at St. Peter's Basilica, but his tomb was destroyed during the demolition of the old basilica in the seventeenth century.
Aftermath
After Theodore's death, both John IX and Sergius III claimed to have been elected pope; the latter was excommunicated and driven from the city, though he did later become pope in 904. John IX held synods reaffirming that of Theodore II, and he further banned the trial of people after their death. In turn, Sergius III later annulled the synods of Theodore II and John IX, and reinstated the validity of the Cadaver Synod.
