Siconulfo (? - † 851), son of the prince of Benevento Sico I of Benevento, was the first prince of Salerno, a principality that broke away from the Principality of Benevento as a result of the struggles that followed the murder of the successor of Sico and brother of Siconulfo, Sicardo, prince of Benevento (832-839), who was assassinated by the usurper Radalgiso. In response to the murder of his brother, the people of Salerno proclaimed prince Siconulfo, opposing the wishes of the usurper Radalgiso, who had him prisoner in the city of Taranto. Siconulfo was released by people from Salerno and Amalfi who stormed his prison disguised as Amalfi merchants, rescued him and brought him to Salerno.

It was Radalgiso who first summoned Saracen mercenaries against Siconulf in 841, although Siconulfo soon responded by doing the same against his opponent. The war lasted ten years, during which the ravages of the Saracens worsened and many churches were destroyed. Finally, in 849, the king of Italy and co-emperor of the Holy Empire Louis II the Younger, mediated in the conflict, and confirmed the division of the principality beneventano, forcing the two rivals to sign a peace and making Siconulfo prince of Salerno. The principal cities of the new principality were Taranto, Cassano, Cosenza, Paestum, Conza, Sarno, Cimitile (Nola), Capua, Tano and Sora.

Siconulfo died shortly afterwards in 851 and succeeded his son Sico II, who ruled in minority, being the royal power managed by his godfather and regent of the Principality of Salerno, Pedro de Salerno. Sources

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