Otho I, the Great, a German emperor, born in 912, died at Memleben, Thuringia, May 7, 973. In spite of strong opposition to him in his own family, he succeeded his father, Henry the Fowler, and was crowned at Aix-la-Cha-pelle in 936. His whole reign of 36 years was a constant series of long and bloody wars. After quieting the opposition to himself, he was engaged in a struggle from 938 to 950 with Boleslas, duke of Bohemia, who was finally subdued and obliged to reinstate the Christian religion. He was also involved in a war with the dukes of Bavaria and Franconia, in which he was triumphant; and he strengthened his authority still more by conferring the duchy of Swabia upon his son Ludolph, that of Bavaria upon his brother Henry, and that of Lorraine upon his son-in-law Conrad, count of Worms. No less successful against foreign enemies, he made the Slavic tribes tributary as far as the Oder, and drove back the Danes, who had invaded Germany, and compelled their king to acknowledge his. authority. In 946 he undertook a journey to France to aid his brother-in-law Louis (Outremer) against Hugh the Great, count of Paris, and, composing the differences between the king and his vassals, received as a reward all of Lorraine that was still in French hands.
Invited by Adelaide of Burgundy, the beautiful widow of Lo-thaire of Italy, whose throne had been usurped by Berenger II., he crossed the Alps in 951, defeated Berenger, took Pavia, was crowned king of Lombardy, married Adelaide, and returned to Germany. But on account of Otho's affection for his wife, and fur Henry, duke of Bavaria, the enemies of both, headed by Ludolph, his son by his first wife (Eadgith, sister of the English king Athelstan), and by Conrad, duke of Lorraine, raised a civil war, which was not quelled till 954. In the mean time the Hungarians had invaded Germany, and, renewing their incursions in 955, besieged Augsburg, and were defeated (Aug. 10) on the Lechfeld near that city with terrible slaughter. Berenger revolting, Otho again passed over into Italy, was crowned king of that country by the archbishop of Mentz, and on Feb. 2, 962, was crowned emperor of the West by Pope John XII. The pope after his departure breaking his allegiance, Otho hastened again to Italy, and called a council which de-posed John, and chose in his place Leo VIII. The Romans having soon after expelled Leo and recalled John, Otho returned, besieged and took Rome, deprived Benedict V., the successor of John, of his popedom, and reinstated Leo. His plan of forming an alliance with the Greek empire, by marrying his son Otho to Theophania, daughter of Romanus II., having been defeated by the obstinacy of the Byzantine court, Otho invaded lower Italy, defeated the Greeks, and took Apulia and Calabria. The new emperor of the East, John Zimisces, hereupon consented to an alliance.