Germany was formally under the control of the Holy Roman Empire, though that name did not actually appear until 1254. In any case, the Holy Roman Empire was—to quote a joke almost as old as the Middle Ages—neither holy, nor Roman, nor an empire. In fact it was a mask for the German empire, itself a loose collection of duchies such as Saxony and Bavaria. Each had its ruling nobles, and with the end of Carolingian power in 911, these began electing kings to lead the various German states.
The election of Saxony's king Henry, father of Otto the Great, in 918 led to a century of Saxon domination. Otto vastly expanded Germany, transforming the kingdom into a true empire. His victories over the Slavs to the northeast added lands that would become Prussia, or eastern Germany, and the conquest of the Magyars in the southeast led to the establishment of the "eastern kingdom"—Osterreich, or Austria. To the southwest, Otto reconquered territories formerly controlled by Charlemagne, including Lorraine and Burgundy, today in eastern France.
With Otto's conquest of Italy and the reviving of the Holy Roman Empire, German kings thenceforth claimed the title of emperor, which they usually received in a coronation ceremony overseen by the pope. Otto's grandson Otto III (ruled 983-1002), whose mother was a Byzantine princess, grew up nourished on grand dreams of an empire. He believed that the empire could become more than just a name. As emperor, he presented a crown to his counterpart in Byzantium, proclaiming him ruler of the East as Otto was of the West. The Byzantines, however, had no interest in an alliance, and Otto's magnificent visions of an empire died with him.