Otherwise known as
Elector Frederick or Frederick the Wise. He ruled Electoral
Saxony (as opposed to Ducal
Saxony) between 1486 and 1525.
As an elector he wielded great political power in the Holy Roman Empire. This enabled to him offer protection to Martin Luther, protection that was one of the major factors in the early establishment of the Reformation in Germany.
He did not gain the title Frederick the Wise for no reason and he was a very well respected by both other princes and the people. He was renonwned for making well thought out decisions.
He never converted from catholicism to Lutheranism or any form of protestantism, the reason he did not want to hand Luther over to the Roman Catholic Church was because he resented their taxing of his state and the control the exercised over his state. He also felt that Luther's arguments should be more carefully considered before he was condemned.
He managed to use Luther as a tool to demonstrate his defiance against the both the Holy Roman Emperor, Charles V, and the Pope. This defiance was stirred by his dislike of both increased Papal and Imperial control over his state, which he considered autonomous.