Frederick I., emperor of Germany, sur-named Barbarossa (Redbeard), son of Duke Frederick II. of Swabia, and Judith, daughter of Henry the Black, duke of Bavaria, born in 1121, drowned in Asia Minor, June 10, 1190. His uncle, Conrad III., the first German emperor of the house of Swabia (Hohenstaufen), had so entirely won the confidence of the princes and nobles of both Italy and Germany, that upon his recommendation Frederick, then duke of Swabia, was unanimously elected his successor (1152). After reducing several revolted Italian cities and receiving the crown of Italy at Pavia, he went to Rome, reestablished the pope's supremacy there, which had been shaken by Arnold of Brescia, and was crowned emperor, but not until the pope (Adrian IV.) had obliged him to perform several humiliating ceremonies. His next care was to pacify the empire by settling the disputes between the archbishop of Mentz and the count palatine of the Rhine, and the difficulties concerning the duchy of Bavaria. He reduced Boleslas of Poland to vassalage, and in six years had restored the empire to the prosperity which it enjoyed under Henry III. He now turned his attention again to Italy, where the smaller towns were oppressed by Milan, and in 1158 he appeared before that city with 115,000 troops and forced it to submission.

Crema was destroyed after a terrible siege (1160). Milan soon rebelled again, and its fortifications were destroyed and its inhabitants exiled. Meanwhile Pope Adrian had died (1159), and Alexander III. been chosen to succeed him. Frederick supported an anti-pope, Victor V. (or IV.), and Alexander fled to France. Victor died in 1164, and the emperor thereupon set up another antipope, who took the name of Pascal III., and crowned the emperor and his consort a second time in the church of St. Peter at Rome in 1167. The Lombard cities had formed a powerful league against Frederick, and a terrible pestilence which broke out in his army forced him to return to Germany in disguise, with only a few followers. The defences of Milan were then restored, and a new city sprang up in a beautiful and naturally fortified spot, which in honor of the pope and in defiance of the emperor was called Alexandria or Alessandria. During this time Frederick was busily engaged in regulating the affairs of Germany and strengthening his own power. In the autumn of 1174 he invested Alessandria, and besieged it for five months, during which his army suffered greatly.

The Lombards came to the relief of the city, and on May 29,1176, a decisive battle was fought near Legnano, in the vicinity of the lake of Como, in which Frederick was defeated with great loss, and was supposed for some days to have been killed. He reappeared at Pavia, where the empress had already put on mourning, acknowledged Alexander as pope, and in July, 1177, held an interview with him at Venice, in which a complete reconciliation was effected, Frederick humbling himself again at the pope's feet, and receiving from him the kiss of peace. The cities of Lombardy obtained a truce for six years. New troubles were now raised in Germany by the ambitious duke Henry the Lion. He was finally subdued, and banished for three years. The Lombard truce was followed in 1183 by a definitive treaty of peace on terms honorable to all parties, and when Frederick made a journey to Italy soon afterward he was received with acclamations of joy. Tranquillity reigned in all his dominions when the news of the fall of Jerusalem in 1187 caused Pope Clement III. to proclaim the third crusade.

The old emperor took the cross, and in the spring of 1189 put himself at the head of 150,000 warriors, crossed Hungary, severely punished the Greeks, whom he suspected of treachery, penetrated into Asia Minor, defeated the Moslems in several engagements, and took Iconium (Konieh). The army reached the banks of the Seleph or Calycadnus in Cili-cia, June 10, 1190. The vanguard had crossed by a bridge, when the emperor, impatient to join his son, Duke Frederick of Swabia, who led the advance, plunged with his war horse and heavy armor into the stream, was overpowered by the current, and was borne away. Some historians have preferred a less well authenticated account that he lost his life in consequence of bathing, like Alexander, in the Cydnus. Frederick was a man of noble qualities, of great mental endowments, and of spirit equal alike in reverses and prosperity, though somewhat arrogant and not seldom cruel in the heat of war. He was a patron of letters and a man of learned accomplishments, and remarkable for elegance and majesty of aspect.

He wrote memoirs of some parts of his life, which he left to Otho, bishop of Freising. After divorcing his first wife (1156), he married Beatrice of Burgundy. His son Frederick, founder of the Teutonic knights, lost his life in the third crusade, and another son, Henry VI., succeeded to the empire.