Vergilius et duo miracula Leonis IV (Liber Pontificalis 105.19-20)

The life of pope Leo IV in the Liber Pontificalis relates that he drove out a dangerous basilisk who lived under the church of St. Lucy in Rome. He worked this miracle during the procession for the feast of the Assumption of Mary, while being accompanied by many people (magna comitante caterva, according to the Latin text). This expression is taken from Vergil's Aeneid (Aen. 2.40, 2.370 or 5.76) and is always used in episodes dealing also with a serpent. The following miracle of Leo, namely arresting a fire which threatened St. Peter's basilica thanks to his prayers, is again reminiscent of the fifth book of Vergil's Aeneid, where a heavy rain extinguishes a fire thanks to Aeneas, who addresses a prayer to Jupiter. It is likely that the pope was portrayed as similar to Aeneas because St. Peter and St. Paul had been sacked by the Saracens in 846, a year before his election, and this calamity, which was possibly reminiscent of the fall of Troy in the eyes of a few Romans, could be overcome only by a new Aeneas, willing to build a new Rome and provide for the future of its inhabitants.