It was then, by means of an instrument still very uncertain, that the papacy was forced to govern its new state, and in these circumstances, friendly relationship with Constantinople daily becoming more impossible, it is not surprising that we see the pope making an attempt to come to some sort of permanent reconciliation with Desiderius; and indeed when pope Paul died in 767 undoubtedly a peace had been arranged.
All might have been well if pope Paul's successor had been regularly chosen; but a layman Constantine was elected by a rabble at the instigation of his brother Toto of Nepi. Christopher and his son Sergius, who held two of the greatest offices in the papal chancery, decided to call in the aid of the duke of Spoleto to attack Constantine, Rome was entered, and in the appalling confusion the Lombards elected a certain priest named Philip to be pope. Christopher appeared, Philip was turned out, and Stephen III., a Sicilian, was regularly chosen. That was in 768, and in the same year king Pepin died and was succeeded by his two sons, Charles to whom apparently fell Austrasia and Neustria, and Carloman who took Burgundy, Provence, and Swabia.
The death of Pepin left the papacy without a champion. Nor was this all, as soon appeared. Charles and Carloman began to quarrel and to effect their reconciliation, or to avert its consequences, Bertrada, their mother, counselled and succeeded in forcing upon them a friendship and an alliance with the Lombards which meant the complete abandonment of Italy upon the part of the Franks. This alliance was to be secured by a double marriage. Charles was to marry Desiderata, the daughter of the Lombard king, while Gisila, Bertrada's daughter, was to marry Desiderius' heir. It is obvious that S. Peter was in peril, nor was pope Stephen slow to denounce the whole arrangement. His remonstrance, however, was ineffectual and there remained to him but one thing to do: to arrange himself with the now uncurbed Lombard king. This was exceedingly difficult, because his own election had been achieved only by the humiliation of the Lombards. However, he managed it at the price of civil war. Desiderius and his army entered Rome at the behest of the pope, who celebrated Mass before the king in S. Peter's. The Franks were checkmated.
It was not long before Charles saw that he had been outwitted. An immediate change of his policy was necessary. In 771 it came with the repudiation of Desiderata, who was sent back to her father's court at Pavia. Henceforth Charles and Desiderius were implacable enemies. And now everything went in favour of the papal policy, just as before everything had seemed to cross it. Carloman, who had not quarrelled with Desiderius, and might have opposed Charles and changed all the future, suddenly died in December of the year of the quarrel. Charles became thus sole king of the Frankish nation. When pope Stephen came to die in February 772 he must have laid him down with a quiet mind.
In Stephen's stead there was elected as pope a pure Roman, born in the Via Lata of the nobility of the City; he took the famous name of Hadrian I. Desiderius, who had watched with a growing anxiety the amazing policy of Stephen, now turned to his successor, and both demanded and begged a renewal of friendship. Hadrian answered his ambassador at last with the mere truth. "How can I trust your king when I recall what my predecessor Lord Stephen of pious memory told me in confidence of his perfidy? He told me that he had lied to him in everything as to the rights of Holy Church, though he swore upon the body of the Blessed Peter…. Look you, such is the honour of king Desiderius and the measure of the confidence I may repose in him."
Desiderius' answer was not to the point. He seized the cities of Faenza, Ferrara, and Comacchio and ravaged the territory about Ravenna, burned the farms and carried off the cattle. Then he fell upon the Pentapolis, seized Sinigaglia, Jesi, Urbino, Gubbio, S. Leo, and other "Roman" cities, and indeed possessed himself of everything save only Ravenna and Rimini, and proceeded upon a raid into the duchy of Rome.
The answer of the pope was mild but firm: mild, for the hour was not yet come; firm, for it would strike ere long. "Tell your king," said he, "that I swear in the presence of God that if he choose to restore those cities which in my time he has taken from S. Peter, I will hasten into his presence wherever he may appoint a meeting place, at Pavia, Ravenna, Perugia, or here in Rome, that we may confer together…. But if he does not restore what he has taken away he shall never see my face."
The hour was not come. Charles was busy with the Saxon hordes upon the north and east of his kingdom. It was not till the beginning of January 773 that the pope sent his messenger Peter to summon him to his aid. Meanwhile, Desiderius marched on Rome. But even without Charles the pope was not defenceless. The Vicegerent of God who had without a soldier turned back Attila on the Mincio and had thrust back Liutprand from Rome was not to be at the mercy of such a king as Desiderius. At Viterbo his messengers, the three bishops of Albano, Palestrina, and Tivoli, met the Lombard king and gave him the pope's last word: "Anathema." Desiderius shrank back. In that moment as it seems the ambassadors of Charles arrived in Rome, satisfied themselves of the justice of the papal summons, and carried back to the great Frank the prayer of the pope that he would "redeem the Church of God." In the late summer of that year the Frankish host was assembled at Geneva and was already beginning to cross the mountains in two mighty commands by the Great S. Bernard and the Mont Cenis; in October the siege of Pavia was begun.
That siege endured for more than eight months. Meanwhile Charles had made himself master of Verona and of many of the cities of the plain. The men of Spoleto hastened to "commend" themselves to the pope and the citizens of Fermo, Osimo, and Ancona, and of Citta di Castello, we read, followed their example, and for the feast of Easter 774, Charles appeared in Rome, and was greeted and embraced by the pope at S. Peter's. On Easter Day Charles heard Mass in S. Maria Maggiore, on Easter Monday in S. Peter's, on Easter Tuesday in S. Paul's. On the Wednesday in that Easter week, according to Hadrian's biographer, he made that great Donation to the papacy which confirmed and extended and secured the gift of Pepin his father. The duchies of Spoleto and Benevento, and much else, were added to the exarchate "as it was of old" and given to the pope. Then in June Pavia, the Lombard capital, fell and Desiderius and his wife were sent by Charles as prisoners to a convent in Picardy where it is said they ended their lives.
[Illustration: GUARDHOUSE OF THE PALACE OF THEODORIC]