Maximilian I, Holy Roman Emperor

Maximilian was the only surviving son of Frederick III and ran a joint government with his father from 1486 until Frederick's death in 1493. His 1477 marriage to Mary, Duchess of Burgundy expanded Habsburg influence through war, though the family lost its Swiss lands to the Swiss Confederacy. By marrying his son Philip the Handsome to Joanna of Castile in 1496, he positioned his grandson Charles V to hold both Spanish thrones. Called "Heart of steel" for either courage or ruthlessness, he became known as "the last knight" — though scholars still argue whether he was a medieval dreamer or a cal…