The response of Adelchis to this action was to imprison and rob the emperor while he was staying in the princely palace at Benevento in August—a treachery lamented in a contemporary poem, the Rythmus de captivitate Ludovici imperatoris. A month later, the Saracens had landed with a new invasive force and Adelchis released Louis to lead the armies against it. Adelchis forced Louis to vow never to reenter Benevento with an army or to take revenge for his detention. Louis went to Rome in 872 and was released from his oath by Pope Adrian II on 28 May. He tried to exact punishment on Adelchis, but was not very successful. Adelchis turned to the Byzantines. He was assassinated in May 878.
