Short answers, pulled from the story.
Stupor mundi, meaning Wonder of the World, was the Latin appellation given to Frederick II by contemporaries to reflect his extraordinary range of talents and activities. He spoke six languages, wrote poetry, studied mathematics and natural philosophy, issued landmark legal codes, and led diplomacy with Islamic rulers while simultaneously governing an empire stretching from Sicily to Germany.
Frederick II was excommunicated four times between 1227 and his death in 1250. The first excommunication came in September 1227, issued by Pope Gregory IX for failing to go on crusade. The second followed in 1228 when Frederick sailed to the Holy Land while still excommunicated. The third and fourth came later during his prolonged wars with the papacy.
Frederick II secured Jerusalem through direct diplomatic negotiations with the Ayyubid sultan Al-Kamil, signing the Treaty of Jaffa on the 18th of February 1229. The treaty returned Jerusalem, Nazareth, Bethlehem, and a coastal strip to the Kingdom of Jerusalem for ten years, while the Dome of the Rock and al-Aqsa Mosque remained under Muslim control. The agreement was condemned by the Templars, Hospitallers, and the Latin Patriarch of Jerusalem.
The Constitutions of Melfi, issued in 1231, were a comprehensive legal code that centralized royal authority across the Kingdom of Sicily. The code replaced clerical officialdom with lay jurists trained in Roman law and established a hierarchical administrative system reaching from the emperor to the most subordinate provincial official. Frederick conceived of the code as the model framework for his larger territorial empire.
Frederick II spoke six languages: Latin, Sicilian, Middle High German, Old French, Greek, and Arabic. He had acquired several of these during his childhood in cosmopolitan Palermo, and by the time he was declared of age in 1208 he already spoke five.
Frederick II died on the 13th of December 1250, and the House of Hohenstaufen did not survive long after him. The Holy Roman Empire entered a long period of decline during the Great Interregnum. The Kingdom of Sicily, which had been the foundation of his power, eventually fell to the Angevins later in the 13th century.