Pope Gregory IX would give no quarter, and excommunicated the Emperor because he had been unable to go on a crusade owing to pestilence in his army. The clergy were bidden to assemble in the Church of St Peter and to fling down their lighted candles as the Pope cursed the Emperor for his broken promise, a sin against religion. The news of this ceremony spread through the world, the two parties appealing to the princes of Europe for aid in fighting out this quarrel. Frederick defied the papal decree, and went to win back Jerusalem from the infidels as soon as his soldiers had recovered. He took the city, but had to crown himself as king since none other would perform the service for a man outside the Church. Frederick bade the pious Mussulmans continue the prayers they would have ceased through deference to a Christian ruler. He had thrown off all the superstitions of the age except the study of astrology, and was a scholar of wide repute, delighting in correspondence with the learned.
The Arabs did not admire Frederick's person, describing him as unlikely to fetch a high price if he had been a slave! He was bald-headed and had weak eyesight, though generally held graceful and attractive. In mental powers he surpassed the greatest at his house, which had always been famous for its intellect. He had been born at Palermo, "the city of three tongues"; therefore Greek, Latin, and Arabic were equally familiar. He was daring in speech, broad in views, and cosmopolitan in habit. He founded the University of Naples and encouraged the study of medicine; he had the Greek of Aristotle translated, and himself set the fashion in verse-making, which was soon to be the pastime of every court in Italy.
The Pope was more successful in a contest waged with tongues than he had proved on battle-fields, which were strewn with bodies of both Guelf and Ghibelline factions. He dined in 1230 at the same table as his foe, but the peace between them did not long continue. In turn they triumphed, bringing against each other two armies of the Cross, the followers of the Pope fighting under the standard of St Peter's Keys as the champion of the true Christian Church against its oppressors.
Pope Innocent IV, who succeeded Gregory, proved himself a very cunning adversary. He might have won an easy victory over Frederick II if the exactions of the Papacy had not angered the countries where he sought refuge after his first failures. It was futile to declare at Lyons that the Emperor was deposed when all France was crying out upon the greed of prelates. The wearisome strife went on till the very peasants had to be guarded at their work by knights, sent out from towns to see that they were not taken captive. It was the day of the robber, and all things lay to his hand if he were bold enough to grasp them. Prisoners of war suffered horrible tortures, being hung up by their feet and hands in the hope that their friends would ransom them the sooner. Villages were burned down, and wolves howled near the haunts of men, seeking food to appease their ravening hunger. It was said that fierce beasts gnawed through the walls of houses and devoured little children in their cradles. Italy was rent by a conflict which divided one province from another, and even placed inhabitants of the same town on opposite sides and caused dissension in the noblest families.
The Flagellants marched in procession through the land, calling for peace but bringing tumult. The Emperor's party made haste to shut them out of the territory they ruled, but they could not rid the people of the terrible fear inspired by the barefooted, black-robed figures, with branches and candles in their hands and the holy Cross flaming red before them.
One defeat after another brought the House of Hohenstaufen under the control of the Church they had defied so boldly. Frederick's own son rebelled against him, and Frederick's camp was destroyed by a Guelf army. The Emperor had lived splendidly, making more impression on world-history than any other prince of that illustrious family, but he died in an hour of failure, feeling bitterly how great a triumph his death would be to the Pope who had conquered.
It was late in the year 1250 when the tidings of Frederick II's death travelled slowly through his Empire. Many refused to believe them, and declared long years afterwards that the Emperor was still living, beneath a mighty mountain. The world seemed to be shaking yet with the vibration of that deadly struggle. Conrad and Conradin were left, and Manfred, the favourite son of Frederick, but their reigns were short and desperate, and when they, too, had passed the Middle Ages were merging into another era. The "two swords" of Papacy and Empire were still to pierce and wound, but the struggle between them would never seem so mighty after the spirit had fled which inspired Conradin, last of the House of Swabia.
This young prince was led to the scaffold, where he asserted stoutly his claim to Naples above the claim of Charles, the Count of Anjou, who held it as fief of the Papacy. Then Conradin dared to throw his glove among the people, bidding them to carry it to Peter, Prince of Aragon, as the symbol by which he conveyed the rights of which death alone had been able to despoil him.