Considered the Charlemagne of Germany, Otto I (936-73) was only twenty-four years old at the time of his accession, but he was already a king in conduct and facility. It was through his canny state-craft and iron will that Otto I became the first Holy Roman Emperor and earned the appellation Otto the Great.
Otto, aware of the merits of ceremony and symbolism, convinced the dukes of Lorraine, Franconia, Swabia and Bavaria to act as his attendants in his coronation at Aachen by Archbishop Hildebert. Although the dukes later rebelled against Otto's increasing power, and convinced his younger brother Henry to join in a plot to depose him, Otto uncovered and outmaneuvered the conspirators. Furthermore, he gave new duchies to his friends and relatives to increase his personal support network, and he gradually subordinated the dukes. Nonetheless, Otto's successors did not inherit his resolution and ability and as a result, medieval Germany was consumed in a contest between feudalism and royalty.
Furthermore, Otto made the German Church a national institution that was only loosely attached to the papacy. He appointed the bishops and Archbishops, as he named the other officials of the government. Otto was able to consolidate the German tribes into a powerful state by utilizing the unifying force of Christianity. At the suggestion of his bishops, Otto attacked the Wends and sought to convert them to Christianity by the sword. He compelled the king of Denmark and the dukes of Poland and Bohemia to accept him as their feudal suzerain. Aspiring to the throne of the Holy Roman Empire, he welcomed the invitation of Adelaide, the widow of King Lothaire of Italy, to rescue her from the indignities to which she had been subjected by the new King Berengar II.
In 951 Otto invaded Italy and married Adelaide, allowing Berengar to retain his kingdom only as a fief of the German crown. However, the Roman aristocracy refused to acknowledge a German as emperor and master of Italy and began a contest that would last for three centuries. Perhaps most importantly, the united armies of Germany, under Otto I, won a decisive victory over the Magyars on the valley of the Lech near Augsburg in 955. The Magyars, who had invaded Germany in 954, were defeated by Otto's reorganized army and Germany won a period of security and peace. After the defeat of the Magyars, Otto was able to devote himself to German internal affairs. He restored order, suppressed crime and for a time, created a united Germany that was the most prosperous state of its time.