Barbarossa (1466–1546) (Redbeard) Name given by Christians to two Muslim privateers in the Mediterranean, Aruj (d.1518) and Khizr or Khayr ad-Din (d.1546). Aruj was killed in battle against the Spanish, but Khayr seized Algiers from Spain (1533), took Tunis (1534), raided Christian coasts and shipping and gained control of the Barbary States. He acknowledged the Ottoman sultan as his overlord, and was commander (1533–44) of the fleet of Suleiman I (the Magnificent), which controlled the e Mediterranean. His forces were defeated by Spain and Italy in the Battle of Lepanto.

Barbarossa nickname (‘Redbeard’) of Frederick I (c.1123–90), king of Germany and Holy Roman emperor.

Barbarossa was the code name for the military operation in which Hitler's armies launched their invasion of the Soviet Union in 1941.

Barbarossa (German King): see ADRIAN IV.