General Notes

Otto I the Great (November 23, 912 - May 7, 973), son of Henry I the Fowler, king of the Germans, and Matilda of Ringelheim, was Duke of Saxony, King of the Germans and arguably the first Holy Roman Emperor. (While Charlemagne had been crowned emperor in 800, his empire was divided amongst his grandsons, and following the assassination of Berengar of Friuli in 924, the imperial title lay vacant for nearly forty years.)  Early reign:  Otto succeeded his father as king of the Germans in 936. He arranged for his coronation to be held in Charlemagne's former capital, Aachen. According to the Saxon historian Widukind of Corvey, at his coronation banquet he had the four other dukes of the empire, those of Franconia, Swabia, Bavaria and Lorraine, act as his personal attendants, Arnulf I of Bavaria as marshall (or stablemaster), Herman of Swabia as cupbearer (lat. pincerna or buticularius), Eberhard III of Franconia as steward, and Gilbert of Lorraine as chamberlain.  In 938, a rich vein of silver was discovered at the Rammelsberg in Saxony. This ore body would provide much of Europe's silver, copper, and lead for the next two hundred years, and this mineral wealth helped fund Otto's activities throughout his reign.  Otto's early reign was marked by a series of ducal revolts. In 938, Eberhard, the new duke of Bavaria, refused to pay Otto homage. When Otto deposed him in favor of his uncle Berthold, Eberhard of Franconia revolted, together with several of the Saxon nobility, who tried to depose Otto in favor of his elder half-brother Thankmar (son of Henry's first wife Hatheburg). While Otto was able to defeat and kill Thankmar in 936, the revolt continued the next year when Gilbert, the Duke of Lorraine, swore fealty to King Louis IV of France. Meanwhile, Otto's younger brother Henry conspired with the Archbishop of Mainz to assassinate him. The rebellion ended in 939 with Otto's victory at the Battle of Andernach, where the dukes of Franconia and Lorraine both perished. Henry fled to France, and Otto responded by supporting Hugh the Great in his campaign against the French crown, but in 941 Otto and Henry were reconciled through the efforts of their mother, and the next year Otto withdrew from France after Louis recognized his suzerainty over Lorraine.  To prevent further revolts, Otto arranged for all the important duchies in the German kingdom to be held by close family members. He kept the now-vacant duchy of Franconia as a personal fiefdom, while in 944 he bestowed the duchy of Lorraine upon Conrad the Red, who later married his daughter Liutgard. Meanwhile, he arranged for his son Liutdolf to marry Ida, the daughter of Duke Herman of Swabia, and to inherit that duchy when Herman died in 947. A similar arrangement led to Henry becoming duke of Bavaria in 949.  Campaigns in Italy and eastern Europe
Meanwhile, Italy had fallen into political chaos. On the death (950), possibly by poisoning, of Lothair of Arles, the Italian throne was inherited by a woman, Adelaide of Italy, the respective daughter, daughter-in-law, and widow of the last three kings of Italy. A local noble, Berengar of Ivrea, declared himself king of Italy, abducted Adelaide, and tried to legitimize his reign by forcing Adelaide to marry his son Adalbert. However, Adelaide escaped to Canossa and requested German intervention. Ludolf and Henry independently invaded northern Italy to take advantage of the situation, but in 951 Otto frustrated his son's and his brother's ambitions by invading Italy himself, forcing Berengar to swear fealty, and then, having been widowed since 946, marrying Adelaide.  This marriage triggered another revolt. When Adelaide bore a son, Ludolf feared for his position as Otto's heir, and in 953 he rebelled in league with Conrad the Red and the Archbishop of Mainz. While Otto was initially successful in reasserting his authority in Lorraine, he was captured while attacking Mainz, and by the next year, the rebellion had spread throughout the kingdom. However, Conrad and Ludolf erred by allying themselves with the Magyars. Extensive Magyar raids in southern Germany in 954 compelled the German nobles to reunite, and at the Diet of Auerstadt, Conrad and Ludolf were stripped of their titles and Otto's authority reestablished. In 955, Otto cemented his authority by routing Magyar forces at the Battle of Lechfeld.  The Ottonian system:  A key part of Otto's domestic policy lay in strengthening ecclesiastical authorities, chiefly bishops and abbots, at the expense of the secular nobility. Otto endowed the bishoprics and abbeys with large tracts of land, over which secular authorities had neither the power of taxation nor legal jurisdiction. In an extreme example, when Conrad the Red was stripped of his ducal title in Lorraine, he appointed his brother Bruno, already the Archbishop of Cologne as the new duke of Lorraine. In the lands Otto conquered from the Wends and other Slavic peoples on his eastern borders, he founded several new bishoprics.  Because Otto personally appointed the bishops, these reforms strengthened his central authority, and the upper ranks of the German church functioned in some respect as an arm of the imperial bureaucracy. Conflict between Otto's successors and the growing power of the Papacy over these powerful bishoprics would, however, eventually lead to the Investiture Conflict and the undoing of central authority in Germany.
Imperial title:  In the early 960s, Italy was again in political turmoil, and when Berengar occupied the northern Papal States, Pope John XII asked Otto for assistance. Otto returned to Italy and on February 2, 962, the pope crowned him emperor. (Translatio imperii.) Ten days later, the pope and emperor ratified the Diploma Ottonianum, in which the emperor became the guarantor of the independence of the papal states. After Otto left Rome and reconquered the Papal States from Berengar, however, John became fearful of the emperor's power and sent envoys to the Magyars and the Byzantine Empire to form a league against Otto. In November of 963, Otto returned to Rome and convened a synod of bishops that deposed John and crowned Leo VIII, at that time a layman, as pope. When the emperor left Rome, however, civil war broke out in the city between those who supported the emperor and those who supported John. John returned to power amidst great bloodshed and excommunicated those who had deposed him, forcing Otto to return to Rome a third time in July of 964 to depose Pope Benedict V (John having died two months earlier). On this occasion, Otto extracted from the citizens of Rome a promise not to elect a pope without imperial approval.  Otto unsuccessfully campaigned in southern Italy on several occasions from 966-972, although in 972, the Byzantine emperor John I Tzimisces recognized Otto's imperial title and agreed to a marriage between Otto's son and heir Otto II and his niece Theophano.  After his death in 973 he was buried next to his first wife Editha of Wessex in the Cathedral of Magdeburg.