Otto I, Holy Roman Emperor

Otto I (23 November 912 – 7 May 973), also known as Otto the Great, was German king from 936 and emperor of the Holy Roman Empire from 962 until his death in 973. He was the oldest son of Henry I the Fowler and Matilda.

Otto inherited the Duchy of Saxony and the kingship of the Germans upon his father's death in 936. He continued his father's work of unifying all German tribes into a single kingdom and greatly expanded the king's powers at the expense of the aristocracy. Through strategic marriages and personal appointments, Otto installed members of his family in the kingdom's most important duchies. This reduced the various dukes, who had previously been co-equals with the king, to royal subjects under his authority. Otto transformed the Roman Catholic Church in Germany to strengthen the royal office and subjected its clergy to his personal control.