Surnamed "Stupor mundi" ("Wonder of the World,") Frederick (1194-1250), was the son of the Holy Roman Emperor Henry VI (the son of Frederick Barbarossa), who was also king of Naples and Sicily. Frederick inherited the Regno (as Naples was referred to) at the age of about three. He did not gain the throne of the Empire unti 1215, after it had passed through several of his uncles. A brilliant man, soldier, politician, diplomat, scholar, Crusader, proto-civil rights leader (he allowed Muslims and Jews complete religious freedon in his realms) and scientist (his book on falcons is still of value), Frederick spent most of his life struggling with the papacy over their respective roles in world affairs. So acrimonious was the relationship that the pope actually excommunicated Frederick for going on Crusade, and even preached a Crusade against him. Frederick was the ancestor of a number of prominant people during the Hundred Years War.