- Frederick Barbarossa, 1123?–90, king of Germany 1152–90; king of Italy 1152–90: emperor of the Holy Roman Empire 1152–90.
- 1194–1250, king of Sicily 1198–1212: as Frederick II, king of Germany and emperor of the Holy Roman Empire 1215–50.
- 1657–1713, king of Prussia 1701–13 (son of Frederick William the Great Elector).
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- See Frederick Barbarossa
- 1657–1713, first king of Prussia (1701–13); son of Frederick William