 After he attained his majority, he commended his duchy to Pepin the Short, King of the Franks, probably at the coaxing of Pope Stephen II, and rebelled against King Desiderius, being deposed in 758 to be replaced by Arechis II.The Roman Emperor Constantine V offered to capture the fleeing Liutprand if Desiderius would attack the papacy until a Roman force from Sicily could join him.Desiderius did not attack and Liutprand was not captured.