DESIDERIUS, King of the Lombards. – He ascended the throne in 757 upon the death of Aistulf, thanks to the promises made to Pope Stephen II to restore the conquests of recent years. He did not, however, carry out this restoration; indeed, upon the death of Paul I in 768, he attempted to influence the election of his successor in Rome with the support of a faction that had formed in the city. Having then gone to Rome in 777, he worked with Stephen III to eliminate the leaders of the opposing faction.
After the election of Pope Hadrian I, DESIDERIUS sought an alliance with Charles, King of the Franks, with the aim of removing the protection that the papacy enjoyed from that quarter and which alone prevented him from securing the conquests in central Italy; he also attempted a new descent upon Rome. But Hadrian convinced King Charles to descend into Italy, and despite the difficulties placed in his way by the Franks themselves, Charles, having overcome the Chiusa in 773, conquered northern Italy, besieged DESIDERIUS in Pavia, took him prisoner in June 774, and interned him together with his wife Anna in the monastery of Corbie, where he died shortly thereafter. Alongside his wife, DESIDERIUS had been a great patron of the monastic movement in his kingdom. With DESIDERIUS, the Lombard kingdom passed under Frankish dominion.