Barbarossa refers to Frederick I, a Holy Roman Emperor who reigned from 1155 to 1190. He was known for his efforts to consolidate the empire and strengthen its authority. His nickname, which means "Red Beard" in Italian, comes from his distinctive facial hair. Frederick I played a significant role in the Crusades, participating in the Third Crusade to reclaim Jerusalem. In addition to his military campaigns, Barbarossa is remembered for his conflicts with the Italian city-states and the Pope. His reign marked a pivotal period in medieval European history, influencing the balance of power between the empire and regional authorities.