Edward III of England
Edward was crowned when he was fourteen years old, after his father was forced to abdicate. After his victory against the Scots, he declared himself heir to the French throne in 1337, and so started the Hundred Years' War. The war went very well for England; the victories of Crécy and Poitiers led up to the Treaty of Brétigny, by which he gained a lot of territory. When he became older, he was much less active, mostly a result of his bad health. He died of a stroke in 1377, aged 64.