The grandson of Frederick I (Barbarossa), Frederick II was known as Stupor Mundi (‘Wonder of the World’) because of the breadth of his power and of his administrative, military, and intellectual abilities. He was crowned King of the Germans in 1215 and Holy Roman Emperor in 1220, but his reign was dominated by a long and ultimately unsuccessful struggle for power with the papacy. In 1228 he led a successful crusade to Jerusalem, obtaining, in 1229, Jerusalem, Nazareth, and Bethlehem for Christendom. Twice excommunicated by Pope Gregory IX, and opposed in Italy by the Lombard League, Frederick devolved a great deal of imperial power within Germany on the lay and clerical princes in an effort to maintain their support, and concentrated on building a power base in Sicily, a process completed by the Constitution of Melfi in 1231. He defeated the Lombard League at Cortenuova in 1237 and humiliated Gregory IX prior to the latter’s death in 1241, but failed in his efforts to conciliate Innocent IV who appealed to Germany to revolt at the Synod of Lyons in 1245. Frederick’s position was crumbling in the face of revolt, papal propaganda, and military defeat when he died in 1250, leaving an impossible situation for his heirs to solve. Many scholars and artists of his court migrated to north Italian cities, becoming precursors of the Renaissance.