ASTOLFO, King of the LONGOBARDS. — He succeeded his brother Ratchis in 749. Resuming the anti-Byzantine policy of his predecessor, before July 751 he had Ravenna occupied, thus putting an end to the exarchate, and then turned his attention toward Rome (752). Stephen II managed to conclude a forty-year peace with him, but A. broke it less than four months later, claiming the right to subject the Romans to an annual gold tribute of one solidus per inhabitant and to bring Rome and the surrounding cities under his jurisdiction. No compromise was possible this time with the Lombard king: the Pope made one last attempt on 14 October 753, going in person to meet him at Pavia, accompanied by the captain of the imperial guard from Constantinople and by two Frankish ambassadors; but A. refused every concession.
Stephen II then proceeded from Pavia to Paris, where Pippin, invested by the Pope with the title of patrician and thereby made defender and protector of the Church of Rome, after repeated and vain attempts to resolve the matter peacefully, decided to wage war against the Lombards.
The Franks, having crossed the Mont Cenis, clashed with the Lombard army at the Clusae near Susa and defeated II. A., besieged in Pavia, was forced to come to terms (755), the conditions being: the restoration of Ravenna and several other cities and the promise never again to molest the Duchy of Rome. The lands thus obtained were ceded by Pippin to the Pope. But once the Franks had withdrawn, A. advanced again with his army toward Rome and on 10 January 756 laid siege to the city. Three months later, however, he was compelled to return to northern Italy to face a second time the Frankish army, which had come once more to the aid of Stephen II. The Lombards suffered a new defeat (the first of 756). A. this time had to accept terms far harsher than those of 755: he had to restore a greater number of cities, namely the Exarchate and the Pentapolis as they had been reduced after the Lombard conquest (Comacchio, Ravenna, and all the territory between the Apennines and the sea, from Forlì to Senigallia, excluding Ancona, Faenza, Imola, and Ferrara). The keys of the cities were delivered to the Pope together with the donation act «to St Peter», to the Holy Roman Republic and to all subsequent Pontiffs, which was then placed in the Confession of St Peter.
A. died in 756, a few months after Pippin had withdrawn to France.