Frederick Barbarossa, after his defeat at the Legnano in 1176 finally (in the Peace of Venice of 1177) recognizes Alexander III as pope. He is seen here kneeling before Alexander in recognition of his spiritual supremacy. Frederick I, 1122 - 1190, aka Frederick Barbarossa. Holy Roman Emperor. Pope Alexander III, c. 1100/1105 - 1181, born Roland of Siena. Pope from 1159 to 1181. From Hutchinson's History of the Nations, published 1915.