After the death of Urban, Pascal II. became pope, and the empire was under the dominion of Henry IV. who came to Rome pretending friendship for the pontiff but afterward put his holiness and all his clergy in prison; nor did he release them till it was conceded that he should dispose of the churches of Germany according to his own pleasure. About this time, the Countess Matilda died, and made the church heir to all her territories. After the deaths of Pascal and Henry IV. many popes and emperors followed, till the papacy was occupied by Alexander III. and the empire by Frederick, surnamed Barbarossa. The popes during this period had met with many difficulties from the people of Rome and the emperors; and in the time of Barbarossa they were much increased. Frederick possessed military talent, but was so full of pride that he would not submit to the pontiff. However, at his election to the empire he came to Rome to be crowned, and returned peaceably to Germany, where he did not long remain in the same mind, but came again into Italy to subdue certain places in Lombardy, which did not obey him. It happened at this time that the cardinal St. Clement, of a Roman family, separated from Alexander, and was made pope by some of the cardinals. The Emperor Frederick, being encamped at Cerma, Alexander complained to him of the anti–pope, and received for answer, that they were both to go to him, and, having heard each side, he would determine which was the true pope. This reply displeased Alexander; and, as he saw the emperor was inclined to favor the anti–pope, he excommunicated him, and then fled to Philip, king of France. Frederick, in the meantime, carrying on the war in Lombardy, destroyed Milan; which caused the union of Verona, Padua, and Vicenza against him for their common defense. About the same period the anti–pope died, and Frederick set up Guido of Cremona, in his stead.
The Romans, from the absence of the pope, and from the emperor being in Lombardy, had reacquired some authority in Rome, and proceeded to recover the obedience of those places which had been subject to them. And as the people of Tusculum refused to submit to their authority, they proceeded against them with their whole force; but these, being assisted by Frederick, routed the Roman army with such dreadful slaughter, that Rome was never after either so populous or so rich. Alexander now returned to the city, thinking he could be safe there on account of the enmity subsisting between the Romans and the emperor, and from the enemies which the latter had in Lombardy. But Frederick, setting aside every other consideration, led his forces and encamped before Rome; and Alexander fled to William, king of Puglia, who had become hair of that kingdom after the death of Roger. Frederick, however, withdrew from Rome on account of the plague which then prevailed, and returned to Germany. The cities of Lombardy in league against him, in order to command Pavia and Tortona, which adhered to the imperial party, built a city, to be their magazine in time of war, and named in Alexandria, in honor of the pope and in contempt of Frederick.
Guido the anti–pope died, and Giovanni of Fermo was appointed in his stead, who, being favored by the imperialists, lived at Montefiascone. Pope Alexander being at Tusculum, whither he had been called by the inhabitants, that with his authority he might defend them from the Romans, ambassadors came to him from Henry, king of England, to signify that he was not blamable for the death of Thomas à Becket, archbishop of Canterbury, although public report had slandered him with it. On this the pope sent two cardinals to England, to inquire into the truth of the matter; and although they found no actual charge against the king, still, on account of the infamy of the crime, and for not having honored the archbishop so much as he deserved, the sentence against the king of England was, that having called together the barons of his empire, he should upon oath before them affirm his innocence; that he should immediately send two hundred soldiers to Jerusalem, paid for one year; that, before the end of three years, he should himself proceed thither with as large an army as he could draw together; that his subjects should have the power of appealing to Rome when they thought proper; and that he should annul whatever acts had been passed in his kingdom unfavorable to ecclesiastical rule. These terms were all accepted by Henry; and thus a great king submitted to a sentence that in our day a private person would have been ashamed of. But while the pope exercised so great authority over distant princes, he could not compel obedience from the Romans themselves, or obtain their consent that he should remain in Rome, even though he promised to intermeddle only with ecclesiastical affairs.
About this time Frederick returned to Italy, and while he was preparing to carry on new wars against the pope, his prelates and barons declared that they would abandon him unless he reconciled himself with the church; so that he was obliged to go and submit to the pope at Venus, where a pacification was effected, but in which the pope deprived the emperor of all authority over Rome, and named William, king of Sicily and Puglia, a coadjutor with him. Frederick, unable to exist without war, joined the crusaders in Asia, that he might exercise that ambition against Mohammed, which he could not gratify against the vicars of Christ. And being near the river Cydnus, tempted by the clearness of its waters, bathed therein, took cold, and died. Thus the river did a greater favor to the Mohammedans than the pope's excommunications had done to the Christians; for the latter only checked his pride, while the former finished his career. Frederick being dead, the pope had now only to suppress the contumacy of the Romans; and, after many disputes concerning the creation of consuls, it was agreed that they should elect them as they had been accustomed to do, but that these should not undertake the office, till they had first sworn to be faithful to the church. This agreement being made, Giovanni the anti–pope took refuge in Mount Albano, where he shortly afterward died. William, king of Naples, died about the same time, and the pope intended to occupy that kingdom on the ground that the king had left only a natural son named Tancred. But the barons would not consent, and wished that Tancred should be king. Celestine III., the then pope, anxious to snatch the kingdom from the hands of Tancred, contrived that Henry, son of Frederick should be elected emperor, and promised him the kingdom on the condition that he should restore to the church all the places that had belonged to her. To facilitate this affair, he caused Gostanza, a daughter of William, who had been placed in a monastery and was now old, to be brought from her seclusion and become the wife of Henry. Thus the kingdom of Naples passed from the Normans, who had been the founders of it, to the Germans. As soon as the affairs of Germany were arranged, the Emperor Henry came into Italy with Gostanza his wife, and a son about four years of age named Frederick; and, as Tancred was now dead, leaving only an infant named Roger, he took possession of the kingdom without much difficulty. After some years, Henry died in Sicily, and was succeeded in the kingdom by Frederick, and in the empire by Otho, duke of Saxony, who was elected through the influence of Innocent III. But as soon as he had taken the crown, contrary to the general expectation, he became an enemy of the pope, occupied Romagna, and prepared to attack the kingdom. On this account the pope excommunicated him; he was abandoned by every one, and the electors appointed Frederick, king of Naples, emperor in his stead. Frederick came to Rome for his coronation; but the pope, being afraid of his power, would not crown him, and endeavored to withdraw him from Italy as he had done Otho. Frederick returned to Germany in anger, and, after many battles with Otho, at length conquered him. Meanwhile, Innocent died, who, besides other excellent works, built the hospital of the Holy Ghost at Rome. He was succeeded by Honorius III., in whose time the religious orders of St. Dominic and St. Francis were founded, 1218. Honorius crowned Frederick, to whom Giovanni, descended from Baldwin, king of Jerusalem, who commanded the remainder of the Christian army in Asia and still held that title, gave a daughter in marriage; and, with her portion, conceded to him the title to that kingdom: hence it is that every king of Naples is called king of Jerusalem.