English form of an Old German name meaning "peaceful ruler", derived from fridu "peace" and rih "ruler, king". This name has long been common in continental Germanic-speaking regions, being borne by rulers of the Holy Roman Empire, Germany, Austria, Scandinavia, and Prussia. Notables among these rulers include the 12th-century Holy Roman emperor and crusader Frederick I Barbarossa, the 13th-century emperor and patron of the arts Frederick II, and the 18th-century Frederick II of Prussia, known a...