Pope Leo IV was pope from 847 to 855.

A Roman by birth, he was unanimously chosen to succeed Sergius II. When he was elected, on April 10, 847, he was cardinal of Santi Quattro Coronati, and had been subdeacon of Gregory IV and archpriest under his predecessor. His pontificate was chiefly distinguished by his efforts to repair the damage done by the Saracens during the reign of his predecessor to various churches of the city, especially those of St Peter and St Paul. The Saracens were sieging Gaeta, and then between 848 and 849 Leo had the walls of the city restored and strengthened. When the Muslims closed to Portus, he summoned the Repubbliche Marinare of Italy cities of Naples, Gaeta and Amalfi to form a league. The command of the unified fleet was given to Cesarius, son of the duke of Naples. The subsequent battle was one of the most famous in the Middle Ages Papacy history, and is celebrated in a famous fresco by Raphael and his pupils in his Rooms of the Vatican Palace in the Vatican City. Another episode of Leo's life celebrated by the Urbinate in his series of frescoes painter is the Incendio di Borgo: it depicts the great burning of the Anglo-Saxon district of Rome (the "Borgo") which, according to the legend, was stopped by Leo simply making the sign of the cross.

In order to definitively counter the Saracen menace, Leo ordered a new line of walls encompassing the suburb on the right bank of the Tiber to be built, including the till now undefended St. Peter's Basilica. The district enclosed by the walls is still known as the Civitas Leonina, namely the City of Leo. He also embellished the damaged churches of St. Paul and St. Peter's: the latter's altar received again (after the former had been stolen) his gold covering, which weighed 206 lb. and was studded with precious gems.

Leo held three synods, one of them in 850, distinguished by the presence of Louis II, but none of them otherwise of importance. The history of the papal struggle with Hincmar of Reims, which began during Leo's pontificate, belongs rather to that of Nicholas I.

Leo died on July 17, 855 and was buried in St. Peter. Benedict III was Leo's immediate successor. A medieval tradition claimed that a woman, Pope Joan, succeeded him, disguising herself as a man; however, Joan is generally believed to be fictitious.

855 deaths | Natives of Rome | Popes | Saints

Lev IV. | Leo IV. (Papst) | Лев IV (папа римский) | León IV (Papa) | Léon IV (pape) | 교황 레오 4세 | Papa Leone IV | IV. Leó pápa | Paus Leo IV | レオ4世 (ローマ教皇) | Leo IV (pave) | Papież Leon IV | Papa Leão IV | Leo IV | 良四世