premise: Henry III assumed the throne when he was 9 years old in 1246.
hypothesis: Henry III ( 1 October 1207 -- 16 November 1272 ) , also known as Henry of Winchester , was King of England , Lord of Ireland and Duke of Aquitaine from 1216 until his death . The son of King John and Isabella of Angoulême , Henry assumed the throne when he was only nine in the middle of the First Barons ' War . Henry supported his brother Richard in his bid to become King of the Romans in 1256 , but was unable to place his own son Edmund on the throne of Sicily , despite investing large amounts of money . Henry and the baronial government enacted a peace with France in 1259 , under which Henry gave up his rights to his other lands in France in return for King Louis IX of France recognising him as the rightful ruler of Gascony . Henry died in 1272 , leaving Edward as his successor .