It was in 1220 that Frederick returned from Germany to Italy, leaving his northern kingdom in the hands of the Archbishop of Cologne, as regent.  At Rome he received the imperial crown from the hands of the pope, and, his first wife dying, married Yolinda de Lusignan, daughter of John, ex-king of Jerusalem, in right of whom he claimed the kingdom of the East.

Shortly afterwards a new pope came to the papal chair, the gloomy Gregory IX., whose first act was to order a crusade, which he desired the emperor to lead.  Despite the fact that he had married the heiress of Jerusalem, Frederick was very reluctant to seek an enforcement of his claim upon the holy city.  He had pledged himself when crowned at Aix-la-Chapelle, and afterwards on his coronation at Rome, to undertake a crusade, but Honorius III., the pope at that time, readily granted him delay.  Such was not the case with Gregory, who sternly insisted on an immediate compliance with his pledge, and whose rigid sense of decorum was scandalized by the frivolities of the emperor, no less than was his religious austerity by Frederick’s open intercourse with the Sicilian Saracens.

The old contest between emperor and pope threatened to be opened again with all its former virulence.  It was deferred for a time by Frederick, who, after exhausting all excuses for delay, at length yielded to the exhortations of the pope and set sail for the Holy Land.  The crusade thus entered upon proved, however, to be simply a farce.  In three days the fleet returned, Frederick pleading illness as his excuse, and the whole expedition came to an end.

Gregory was no longer to be trifled with.  He declared that the illness was but a pretext, that Frederick had openly broken his word to the church, and at once proceeded to launch upon the emperor the thunders of the papacy, in a bull of excommunication.

Frederick treated this fulmination with contempt, and appealed from the pope to Christendom, accusing Rome of avarice, and declaring that her envoys were marching in all directions, not to preach the word of God, but to extort money from the people.

“The primitive church,” he said, “founded on poverty and simplicity, brought forth numberless saints.  The Romans are now rolling in wealth.  What wonder that the walls of the church are undermined to the base, and threaten utter ruin.”

For this saying the pope launched against him a more tremendous excommunication.  In return the partisans of Frederick in Rome, raising an insurrection, expelled the pope from that city.  And now the free-thinking emperor, to convince the world that he was not trifling with his word, set sail of his own accord for the East, with as numerous an army as he was able to raise.

A remarkable state of affairs followed, justifying us in speaking of this crusade as a comedy, in contrast with the tragic character of those which had preceded it.  Frederick had shrewdly prepared for success, by negotiations, through his Saracen friends, with the Sultan of Egypt.  On reaching the Holy Land he was received with joy by the German knights and pilgrims there assembled, but the clergy and the Knight Templars and Hospitallers carefully kept aloof from him, for Gregory had despatched a swift-sailing ship to Palestine, giving orders that no intercourse should be held with the imperial enemy of the church.