OTHO I. (912-973), called The Great, Holy Roman emperor, was born in 912. After the death of his father, Henry, king of Germany, he was elected and crowned king in 936 at Aix-la-Chapelle; and he occupied the throne upwards of thirty-six years. His reign was one of the most momentous in mediaeval history, its chief incident being his assumption of the imperial crown, whereby he rendered impossible the growth of a compact German monarchy. Otho was a man of great ambition, stern and resolute; and soon after his coronation as king of Germany his leading vassals saw that he intended to claim from them something more than nominal allegiance. First he had to suppress a rebellion headed by Eberhard, duke of Franconia, in association with Thankmar, a son of King Henry by a marriage which had been declared invalid. When this insurrection was put down, Thankmar having died, there was a more formidable rising, in which Eberhard secured the alliance of Otho's younger brother Henry, of Giselbert, duke of Lorraine, of Frederick, archbishop of Mainz, and of other powerful prelates. The king was again triumphant, and on this occasion he strengthened his position by retaining Franconia in his own hands, and by granting Lorraine to his supporter Conrad, who married Otho's daughter Liudgard. To his brother Henry, whom he pardoned, he gave Bavaria; and over Swabia, after the death of its duke, he placed his own son Ludolf. His native duchy, Saxony, was entrusted to Count Hermann, called Billung, a brave noble who had distinguished himself in wars on the eastern borders of Germany. Thus all the great offices of the state were held by Otho's kinsmen and friends; and he exercised more direct control over his subjects than any sovereign, except Charlemagne, had done before him. In wars with the Bohemians, the Wends, and the Danes Otho was not less successful. In 951 he crossed the Alps to help Queen Adelaide, and, having conquered Berengar II., he married her and became king of Lombardy. On his return to Germany his son Ludolf rebelled against him, and was aided by Duke Conrad, by Archbishop Frederick of Mainz, and by many discontented magnates. In the midst of the struggle Germany was attacked by the Magyars, whom Duke Conrad had summoned to his aid. This common danger led to the establishment of internal peace, and Otho succeeded in defeating the Magyars. When in 955 they returned in greater numbers than ever, he inflicted on them so decisive a defeat that they did not again invade Germany. In 961, in response to the appeal of Pope John XII., Otho returned to Italy to punish his rebellious vassal Berengar; and on the 2d February 962 he was crowned emperor by the pope, for the deposition of whom he soon after-wards summoned a council. At this time Otho remained two years in Italy, and a later visit extended over six years, during which he not only maintained his authority in Lom-bardy, but sought to assert it in southern Italy. In Germany his policy was directed chiefly to the strengthening of the church, which was to act as a counterpoise to the influence of the secular nobles. He died on the 7 th May 973, at Memleben, and was buried in Magdeburg, which he had made the seat of an archbishopric.

See Kopke and Dummler, Kaiser Otto der Grosse, 1876.