ADELCHIS, prince of Benevento. — He succeeded his brother Radelgaisus in 853, at a particularly stormy moment. He was repeatedly defeated by the Saracens who were then marauding throughout southern Italy and was forced to pay tribute and give hostages. He managed to recover the occupied territories during the campaign conducted against the Saracens by Louis II, which ended gloriously in February 871 with the capture of Bari. Later, however, realizing the emperor’s intention to bring Benevento under his direct control, he boldly revolted, took Louis II prisoner, and did not release him until forty days later, on 17 September 871, after having made him swear not to seek revenge and not to enter his principality with arms again.
Once the emperor had definitively left southern Italy and the war with the Saracens flared up again, Adelchis was defeated at the Ofanto River and was forced to join the Arab-Campanian league, as many other Lombard princes and dukes had already done.
He fought once more against the Byzantines, who had suddenly occupied Bari, and was killed by his own relatives in the spring of 878 as he was returning from the inspection of a castle. Adelchis deserves credit for having renewed the old Lombard legislation by adding capitularies to it, prefaced by an introduction.