INNOCENT IV

born 12th century, , Genoa died Dec. 7, 1254, Naples original name Sinibaldo Fieschi one of the great pontiffs of the Middle Ages (reigned 124354), whose clash with Holy Roman emperor Frederick II formed an important chapter in the conflict between papacy and empire. His belief in universal responsibility of the papacy led him to attempt the evangelization of the East and the unification of the Christian churches. Additional reading A biographical source (in Italian) is F. Podesta, Innocenzo IV (1928). Among the general histories that have best elaborated the period and the work of Innocent IV is A. Fliche and V. Martin (eds.), Histoire de l'glise depuis les origines jusqu' nos jours, vol. 10 (1950). On Innocent's political relations with the Emperor, see J.M. Powell, Frederick II and the Church: A Revisionist View, Catholic Historical Review, 48:487497 (1963). An important English-language source dealing with the period of Innocent IV is J.A. Watt, The Theory of Papal Monarchy in the Thirteenth Century: The Contribution of the Canonists (1966).