Formosus (fôrmōˈsəs) [key], c.816–896, pope (891–96), probably a Roman; successor of Stephen VI. Under Pope Nicholas I he had been bishop in Bulgaria, where he pursued a rigorous Romanizing campaign. Recalled to his diocese of Porto, he became influential in the church. He was excommunicated by Pope John VIII for leading the party that opposed John's coronation of Charles the Bald. Later, he was restored and was subsequently elected pope. Involved in the dispute over the imperial power, he sided against the dukes of Spoleto, whose growing power was menacing the papacy. However, he was forced to crown Guido, duke of Spoleto, and his son Lambert. Formosus encouraged the German claimant, Arnulf, to invade Italy and crowned (896) him emperor. After Formosus' death, the Spoletos came into power. He was succeeded by Boniface VI. Formosus' grave was desecrated, and his pontificate declared invalid. In 897 he was reinterred, and Pope John XI validated his acts.