A new struggle between pope and king, sparked by the efforts of Emperor Frederick I Barbarossa (bar-buh-ROH-suh; "Red Beard"; ruled 1152-90) to forge a single German state, began in the 1150s. Frederick set out to subdue all rival princes, and initially allied himself with Adrian IV, history's only English pope. Soon afterward, however, Frederick broke off the alliance.
He invaded northern Italy in 1154, and after twenty years of fighting, he succeeded only in making himself more and more unpopular with the Italians. One of his most bitter foes was Pope Alexander III (ruled 1159-81), against whom Frederick supported an antipope. Alexander countered by helping to organize the Lombard League, an alliance of cities opposed to Frederick. In 1175 Frederick also had a falling-out with Henry the Lion, Duke of Saxony and a member of the powerful Welf family. Soon Frederick's Italian opponents began calling themselves Guelphs (GWELFZ), and joined forces with the church against the emperor and his supporters, the Ghibellines (GIB-uh-leenz; see box, "Church vs. State vs. People").
Frederick suffered a major military defeat in 1176 and made a truce with Alexander a year later. The Peace of Constance in 1183 gave Lombard League cities their freedom. Frederick had meanwhile turned his attention to his homeland, where he adopted an entirely new strategy, supporting the German noblemen he had once opposed. To give the nobles more power, he adopted feudalism, which had long since taken hold in France and England. The resulting peace and unity among the Germans made him one of his nation's greatest heroes.
World History
