Otto I (Holy Roman Empire)

Otto I (Holy Roman Empire), called Otto the Great (912-973), Holy Roman emperor (962-973), king of Germany (936-973), the son of the German king Henry I. After subduing an uprising of nobles incited by his brother, Otto consolidated his kingdom by granting duchies to faithful relatives and followers. In 951 he marched to Italy to assist Adelaide, the widowed queen of Lombardy, against Berengar II, who had usurped the kingdom. Otto defeated Berengar and married Adelaide, thereby becoming ruler of northern Italy. When he returned to Germany, he again crushed a rebellion of nobles led by his son Liudolf and halted a Hungarian invasion in 955. In 962 he was crowned Holy Roman emperor. In 963 he deposed Pope John XII and had Leo VIII elected in his stead. Otto sought to make the church subordinate to the authority of the empire but assisted in spreading Christianity throughout his domain. He negotiated unsuccessfully with the Byzantine emperor Nicephorus II Phocas for an alliance between the Byzantine and Holy Roman empires, but was able to arrange a marriage between his son Otto II and Theophano, daughter of the Byzantine emperor Romanus II.