Pope John VIII (Latin: Ioannes VIII; died 16 December 882) was the bishop of Rome and ruler of the Papal States from 14 December 872 to his death. He is often considered one of the ablest popes of the 9th century.John devoted much of his papacy attempting to halt and reverse the Muslim gains in southern Italy and their march northwards. When his efforts to obtain assistance from either the Franks or the Byzantines failed, John strengthened the defenses of Rome. He supported Methodius of Thessalonica in his mission to the Slavs, defended him against the Carolingian rulers and Bavarian clergy, and authorized the translation of the Bible into Slavonic. John also extended diplomatic recognition to the Duchy of Croatia and resolved the Photian schism. John's pontificate ended with his assassination, and the papacy became significantly weaker in the aftermath.