9. Charles VI of France
He was the king of France who inherited the throne at 11 years of age, in the midst of the Hundred Years’ War. Up until the age of 21 when he assumed real power, he was under the influence of his four uncles. After he dismissed his uncles, brought back his father’s former advisers and earned the epithet “the Beloved.” Then he suddenly started suffering from bouts of insanity that later occurred more frequent and stayed for longer durations. He suffered from delusions, thought he was made of glass, denied knowing his wife or children, went on to attack servant, ran like mad, among another thing. Unable to rule, he was dethroned by princes of the blood.