 Although it owed allegiance at its foundation to the Carolingian emperor, it was "de facto" independent throughout its history and alternated its allegiance between the Carolingians and their successors in the West and the Byzantine emperors in the east.In 839, the prince of Benevento, Sicard, died.Immediately, his chief army officer, Radelchis, seized power in Benevento and imprisoned Sicard's heir and brother, Siconulf, in Taranto.