Zachariah, a Greek by birth, accepted the succession left vacant by Gregory III. under such critical circumstances; but he negotiated so skilfully with Luitprand, that the king not only gave back to the pontifical domain four towns which he had already seized, but further added, as an irrevocable gift, the territories of the Sabines, Narnia, Ossimo, and Ancona, and consented to evacuate the exarchy of Ravenna, occupied by his troops. Zacharias enjoyed an equal amount of credit with the Emperor Constantinus Copronymus, who granted him, in the interest of the Roman Church, concessions which were more than could have been expected from an irritated suzerain. All the sovereigns of his time seemed anxious to have recourse to his advice. Charlemagne, son of Charles Martel, and Rachis, King of the Lombards, went to Rome for the purpose of seeing him, and he invited both of them to enter the monastery of Monte-Cassino. Stephen III., elected by acclamation to succeed Zachariah (752), was carried from the public square to the Lateran Church upon the shoulders of his supporters; and this custom has since been adhered to in cases where the election has been unanimous. He had concluded peace for forty years with Astolfo, King of the Lombards, but that ambitious monarch failed to keep his engagements, as, a short time afterwards, he drove the exarch Eutychius out of Ravenna, and then, claiming for himself all the rights of the emperor, he aspired to become master of Rome (753). This unjust warfare was fortunately carried on so slowly that the sovereign-pontiff had time to go to France and intercede with King Pepin for help against Astolfo. The French army was sent over the Alps, and Astolfo had to submit, and to hand over Ravenna to the people, and surrender the hostages. Stephen returned to Rome, accompanied by Prince Jérôme, the brother of Pepin; but in the following year Astolfo again took up arms, and Pepin, who had again crossed the Alps, this time compelled him to abandon definitely the exarchate of twenty-two towns, together with the territories attached to them, which he made over absolutely to St. Peter and his successors. This, with the Duchy of Rome, constituted the temporal dominion of the Church. A few years later Adrian I., who had avoided falling into the political snares laid for him by Didier, appealed to Charlemagne for his intervention, and the latter, crossing the Alps, laid siege to Pavia, the capital of the Lombard kings, took Didier prisoner, and sent him to the monastery of Corbie. Not content with delivering Rome, Charlemagne, during the two visits which he paid to that city, during and after the war, confirmed the gift solemnly made by his father of the territories which were to be inalienably annexed to the Holy See; and, at the same time, he added the coast of Genoa, Corsica, Mantua, Venetia, Istria, the duchies of Spoleto, Benevento, and the entire exarchate over its thirty towns.