by Charlemagne, succeeded as prince of Benevento. Unwisely, Charlemagne released Grimoald in return for an oath of loyalty. Grimoald did not keep his promise; by c. 791, he had effectively proclaimed himself independent and successfully resisted the Franks. Grimoald later tried to throw off Frankish suzerainty, but Charlemagne's sons, Pepin of Italy and Charles the Younger, forced him to submit in 792. Notes Bibliography Einhard. The Life of Charlemagne. Translated by Samuel Epes Turner. 730s births 787 deaths Year of birth uncertain Dukes of Benevento Lombard warriors Princes of Benevento 8th-century rulers in Europe 8th-century Lombard people