Till the year 1209, when Frederick took upon himself the govern ment of Lower Italy and Sicily, he was under the guardianship of Innocent III.; but the empress Constance, his mother, was obliged to purchase the investiture of Naples and Sicily, and the coronation of her son, by sacrificing to the pope the most important ecclesiastical rights. The royal crown of Germany, which was adjudged by the German princes to the child when only three years of age, was taken, after the death of his father, by the Duke of Suabia, his uncle, who however wore it without advantage in opposition to Otho IV. till he was murdered in 1208 by Otho von Wittelsbach; but Otbo IV. dis pleasing the pope, Innocent himself called Frederick to the throne of Germany. In spite of all the efforts of the party of the Guelphs, Frederick arrived in Germany in 1212, and was received with open arms by the party of the House of Hohenstaufen. The possession of the crowns of Germany and Sicily inspired Frederick with hopes of making himself master of all Italy, subduing Lombardy, and reducing the power of the spiritual monarch to the dignity of the first bishop of Christendom. But he misunderstood the spirit of his age, which was far less enlightened than himself, and still cherished prejudices which he had overcome. If the conception of the plan was great, it was equalled by his prudence in gradually preparing to carry it into effect. In 1220 he caused his eldest son Henry to be chosen king of the Romans, and appeased the anger of the new pope Honorius by alleging that this measure was absolutely necessary before he could proceed to the crusade which he had undertaken, and by promising that he never would unite Sicily with the empire. Disregarding the refusal of the Milanese to place the iron crown on his head, he pro ceeded to Rome, was crowned emperor in 1220, and as such hastened to his hereditary domioions which he had left almost as a fugitive. It was there that preparations were to be made for the crusade, but first of all it was necessary to put an end to the internal troubles of the country. By the advice of Hermann von Salza, grand master of the Teutonic order, Frederick married lolante, daughter of John of Brienne, titular king of Jerusalem, and assumed his father-in-law's title. Meantime the pope granted him a delay for undertaking the crusade ; his chancellor, Peter de Vinci, compiled a new code of laws, the object of which was to settle the authority of church and state, to reconcile the nobility, clergy, citizens, and peasants, and to be adapted to many different nations, Romans, Greeks, Germans, Arabs, Norman; Jews, and French, respecting as much as possible all existing institutions. For the education of his subjects, be founded a university at Naples in 1224 and the medical school at Salerno was very flourishing. The belles-lettres were cultivated at his court, and Frederick himself, some of whose juvenile poems in the Sicilian dialect, at that time the most cultivated, have been preserved to our times, may be considered as one of the first authors of the refined Tuscan poetry. Many eminent artists, Nicola, Masaccio, and Tomasi da Steffani, were patronised by Frederick ; and the collections of works of art at Canna and Naples were founded.
The year 1227 being fixed for the crusade, Frederick proposed before he set out to call a general diet of the empire at Cremona, to satisfy himself of the sentiments of the Lombards and be crowned as their king. But the Milanese refused, renewed their ancient league
with fifteen cities, and intercepted the communication with Germany by occupying the passes of the Alps. For this they were put under the ban of the empire; but Frederick hastening to the crusade, left the management of the affair to the pope, who only proposed a general amnesty, and enjoined the Lombards to furnish 400 horsemen at their expense, for two years, to join the crusade. At this juncture Honorius died, and Cardinal Hugolinus, nephew of Innocent III., was chosen pope by the name of Gregory IX. Resembling, in the energy of his will, Gregory VII., the new pope urged the emperor, who received the cross for the second time from his hands, to fulfil his promise, and did not hesitate to censure the luxurious way of life of the emperor and his court. A great number of pilgrims had assembled hi Italy, but pestilential diseases raged among them, and the emperor himself was ill wheh he embarked with Louis, landgrave of Thuringia. In three days Frederick grew worse, and was obliged to land at Otranto, where Louis Landgrave died. The fleet proceeded only to the coast of the Morea, and the crusade failed. Upon this Gregory excommunicated the emperor, and laid his dominions under an interdict. Frederick however, notwithstanding the death of his wife Iolaute in child-bed, set out on a new crusade in 1228; but Gregory, who had not expected this and thought it improper for a prince under excommunication to go to the Holy War, commanded the patriarch of Jerusalem and the three orders of knights to oppose the emperor in everything, and caused Frederick's hereditary estates to be occupied and laid waste by his soldiers and John of Brienne. Frederick, notwithstanding all this, by an agreement with Kamel, sultan of Egypt, succeeded in making a ten years' truce, and acquired for himself Jerusalem, the holy places, all the country between Joppa, Bethlehem, Nazareth, and Acre, and the important seaports of Tyre and Sidon.
The city of Jerusalem, where Frederick, on the 18th of May, put the crown upon his own head because no priest would even read mass, was laid under an interdict, and Frederick was even betrayed to the sultan, who gave him the first information of it. Frederick hastened back to Lower Italy, and after fruitless negotiations with Gregory re conquered his hereditary estates and defeated all the intrigues of the pope, who was at length obliged (1230) to free him from the excom munication. The Lombards alone would not hear of any terms, pre vented his son Henry from going to the diet at Ravenna, and were not deceived by Gregory's exhortation to peace. While Frederick at last blamed for his excessive love of external pomp, and for the lavish manner in which he rewarded his favourites. It should be added in his praise, that be gave groat encouragement to arts and sciences. He founded the University of Halle, and the Academy of Sculpture and Painting at Berlin. He enlarged his capital by adding to it the suburb called Friederichstadt, built the palace of Charlottenburg, in honour of his second wife, and founded in 1705 the Supreme Court of Appeal.