In the 1220’s, the Arabs of western Sicily became unruly, forcing Frederick to subdue them and to move the entire Islamic population in that part of the island to Lucera, on the mainland. Nonetheless, the Arabs in the regno continued to be treated well, and some of those in Lucera even become the members of Frederick’s bodyguard.

Like his Norman forebears, Frederick supported the arts and learning. He could speak Latin, Greek, German, Sicilian, French, and Arabic, and he brought scholars from all over the known world to his court in Palermo. In 1221, he founded the world’s first public university in Naples, a center of learning that still bears his name. Frederick himself was a member of the Sicilian School of Poetry, which had its origins in the court of Roger II and which numbered many writers who influenced Dante (1265-1321), among them Giacomo di Lentini (13th century) the inventor of the sonnet. Indeed, it was by the Sicilian School that a form of Italian was used to write literature for the very first time.

In 1214, after defeating the army of Otto of Brunswick (1175-1218), a rival for the imperial throne, Frederick pledged to go on a crusade. It was not until 1227, however, after Pope Gregory IX (d. 1241) threatened him with excommunication, that he planned to leave for the Holy Land. While amassing troops in Apulia, however, he was stricken by typhoid and could not continue. The Pope remained incredulous and, in September of that year, he excommunicated the Emperor.

In response, Frederick wrote an open letter to all crusaders and circulated it in many Italian cities. Thus, on Easter Sunday 1228, while Gregory sermonized against the Emperor, the Roman congregation rose up and ran him out of the city.

Frederick II's Castello Ursino, Catania