HE was son of a Roman nobleman, had been educated in the monastery of St. Martin without the walls, and was made by Sergius II. priest of the four crowned martyrs. He was chosen pope after the death of Sergius II. in 847, and governed the Church eight years, three months, and some days. The Saracens from Calabria had lately plundered St. Peter’s church on the Vatican, and were still hovering about Rome. Leo made it his first care to repair the ornamental part of this church, especially the Confession or burying-place of St. Peter with the altar which stood upon it. To prevent a second plundering of that holy place, he, with the approbation and liberal contributions of the emperor Lothaire, enclosed it and the whole Vatican hill with a wall, and built there a new rione or quarter of the city, which from him is called Leonina. He rebuilt or repaired the walls of the city, fortified with fifteen towers. Whilst he was putting Rome in a posture of defence, the Saracens marched towards Porto in order to plunder that town. The Neapolitans sent an army to the assistance of the Romans: the pope met these troops at Ostia, gave them his blessing, and all the soldiers received the holy communion at his hands. After the pope’s departure, a bloody battle ensued, and the Saracens were all slain, taken, or dispersed. The good pope considered the sins of the people as the chief source of public disasters; and being inflamed with a holy zeal, he most vigorously exerted his authority for the reformation of manners and of the discipline of the Church. For this purpose he held at Rome a council of sixty-seven bishops; and among other instances, he deposed and excommunicated Anastasius, cardinal priest of St. Marcellus’s church, because he had neglected to reside in his parish. He received honorably Ethelwolph, king of England, who, in 854, made a pilgrimage to Rome.

Pope Leo directed to all bishops and pastors a Homily on the Pastoral Care, published by Labbe from the Vatican manuscripts, and also extant in the Roman Pontifical. In it all the chief functions of the pastoral charge are regulated, and every duty enforced with no less learning than piety. Among other miracles performed by this holy pope, it is recorded that by the sign of the cross he extinguished a great fire in the city, which threatened the church of the prince of the apostles. He died on the 17th of July, 855, and Bennet III., priest of the church of St. Calixtus, was immediately chosen pope in his room.† He, with many tears, begged that so formidable a burden might not be laid on his shoulders, but could not prevail. Anastasius, the deposed priest, set up for pope, and procured the protection of the emperor Louis II.; but the steady unanimity of the people in the election of Bennet III., over came this opposition, and he was consecrated on the 1st day of September in the same year, 355, as is related by Anastasius, who was then living, and shortly after (before the year 870) Bibliothecarian of the church of Rome, the most learned man and the most shining ornament of that age, as Dr. Cave allows him to have been. See Solier the Bollandist, t. 4, Jul. p. 302.