Leo IV | |
|---|---|
| Bishop of Rome | |
 Contemporary fresco at San Clemente al Laterano | |
| Church | Catholic Church |
| Papacy began | 10 April 847 |
| Papacy ended | 17 July 855 |
| Predecessor | Sergius II |
| Successor | Benedict III |
| Orders | |
| Created cardinal | 844 by Sergius II |
| Personal details | |
| Born | |
| Died | 17 July 855 Rome, Papal States |
| Sainthood | |
| Venerated in | Catholic Church |
| Attributes |
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| Other popes named Leo | |
Pope Leo IV (died 17 July 855) was the bishop of Rome and ruler of the Papal States from 10 April 847 to his death. He is remembered for repairing Roman churches that had been damaged during the Arab raid against Rome, and for building the Leonine Wall around Vatican Hill to protect the city. Pope Leo organized a league of Italian cities who fought and won the sea Battle of Ostia against the Saracens.