Arab raid against Rome (846)
In the 820s, Arabs (known by medieval Italians as the Saracens) began the conquest of Sicily. In 842, Arab forces tried to capture Ponza, but were beaten off by a combined fleet from Naples and Gaeta. However, the same year they took Messina, Sicily. Around the same time Radelchis I of Benevento and Siconulf of Salerno, rivals engaged in civil war, hired Saracen mercenaries to fight in Campania.
The Saracen raiders seem to have known about Rome's extraordinary treasures. Some holy - and impressive - basilicas, such as St. Peter's Basilica, were outside the Aurelian walls, and thus easy targets. They were "filled to overflowing with rich liturgical vessels and with jeweled reliquaries housing all of the relics recently amassed". As a result the raiders pillaged the holy shrines, including St. Peter's basilica. Contemporary historians believe the raiders had known exactly where to look for the most valuable treasures.
Short after the siege Pope Leo IV built a strong wall on the right bank of the Tiber, in order to protect the Church of St. Peter. The encircled territory, defended by Castel Sant'Angelo, was named after the pope Leonine City, and was considered a separate town, with own administration. It joined the city in the sixteenth century, becoming the fourteenth rione of Rome, Borgo. In 849, another saracen raid could be repelled; the city was never again attacked by an Arab fleet.
- Barbara Kreutz (1996). Before the Normans: Southern Italy in the Ninth and Tenth Centuries. University of Pennsylvania Press. pp. 25–28.