On 06 Apr 1264 the future King Edward "Longshanks" I of England (age 24), Philip Marmion 5th Baron Marmion (age 30) and Roger Leybourne (age 49) fought for the King at Northampton Castle [Map] during the Battle of Northampton. Simon de Montfort 6th Earl of Leicester 1st Earl Chester (age 56) fought for the rebels with his son Simon "Younger" Montfort (age 24) who was captured.