Siconulf was the first prince of Salerno, the brother of Sicard, prince of Benevento (832–839), who was assassinated by Radelchis. In response to Sicard's murder, the people of Salerno proclaimed Siconulf prince in opposition to Radelchis. At the time Radelchis was holding Siconulf prisoner in Taranto. A group of people from the cities of Salerno and Amalfi went there in disguise as Amalfian merchants and rescued Siconulf from prison, bringing him to Salerno.