Leo IV

Leo IV was a native of Rome and the son of a man named Radoald (also given as Radwald). He belonged to the Roman clergy and, before his election, served as cardinal-priest of the basilica of the Santi Quattro Coronati on the Caelian Hill. When Pope Sergius II died in January 847, Leo was chosen with unusual speed and unanimity. The haste reflected the continuing danger after the Saracen raid of 846, which had sacked the extra-mural basilicas of St. Peter and St. Paul. He was consecrated on 10 April 847 without waiting for imperial confirmation from the Carolingian court, a mark both of emergency and of the papacy’s growing independence from Frankish oversight. The principal contemporary narrative of his life is the Liber Pontificalis, supplemented by Frankish annals and later Anglo-Saxon and artistic tradition.

His pontificate is remembered above all for the defense and physical restoration of Rome. He repaired churches damaged in 846, including St. Peter’s, and he built a new circuit of walls around the Vatican hill and the Borgo. The work was completed in 852; the enclosure was thereafter called the Leonine Wall and the district the Civitas Leonina. In 849, when a Saracen fleet again threatened the Tyrrhenian coast, Leo blessed a coalition of ships from Naples, Amalfi, Gaeta and other Campanian ports. The ensuing Battle of Ostia ended in a Christian victory, later celebrated in art, notably by Raphael in the Vatican Stanze. A related later legend, also painted by Raphael, credited the pope with extinguishing a fire in the Borgo by making the sign of the cross. He likewise restored his former titular church of the Santi Quattro Coronati.

Leo held a Roman synod in 853 that issued disciplinary canons for the Italian church. In 850 he crowned Louis II as emperor. English sources, especially Asser’s life of Alfred, report that the young Alfred of Wessex visited Rome and that Leo confirmed him and invested him with the insignia of a Roman consul; historians debate the exact character of the ceremony, but the tradition is well attested in Anglo-Saxon historiography. Relations with the Carolingian emperors were generally cooperative, though there were local tensions with imperial officials in the city, including the superista Gratian. Leo also took measures against remaining disciplinary disorders in the Italian church.

He died in Rome on 17 July 855 and was buried in St. Peter’s Basilica. He was succeeded by Benedict III. The medieval legend of Pope Joan, sometimes inserted between Leo IV and Benedict III, has no historical foundation. Leo IV has been venerated as a saint in the Latin Church; his feast is kept on 17 July, the day of his death. Formal papal canonization in the later medieval sense did not yet exist, and his cult rests on early liturgical commemoration and the Roman Martyrology rather than on a named act of canonization.