1. son of Frederick William who in 1701 became the first king of Prussia (1657-1713) • Instance Hypernyms: king, male monarch, Rex • Member Holonyms: Hohenzollern 2. Holy Roman Emperor from 1152 to 1190; conceded supremacy to the pope; drowned leading the Third Crusade (1123-1190) • Syn: Frederick Barbarossa, Barbarossa • Instance Hypernyms: Holy Roman Emperor