Emperor Frederick I, also known as Frederick Barbarossa, was a Holy Roman Emperor who reigned from 1155 until his death in 1190. He is remembered for his efforts to consolidate the empire and strengthen its authority over the various German principalities. Frederick was known for his military campaigns in Italy, where he sought to assert imperial control over the northern city-states. Frederick I was a member of the Hohenstaufen dynasty and played a significant role in the politics of medieval Europe. His reign was marked by conflicts with the papacy and the rise of powerful local rulers. He died during the Third Crusade while crossing the Saleph River in modern-day Turkey.