Henry III granted Kenilworth in 1244 to Simon de Montfort, Earl of Leicester, who later became a leader in the Second Barons' War (1263–67) against the king, using Kenilworth as the centre of his operations. Initially the conflict went badly for King Henry, and after the Battle of Lewes in 1264 he was forced to sign the Mise of Lewes, under which his son, Prince Edward, was given over to the rebels as a hostage. Edward was taken back to Kenilworth, where chroniclers considered he was held in unduly harsh conditions. Released in early 1265, Edward then defeated Montfort at the Battle of Evesham; the surviving rebels under the leadership of Henry de Hastings, Montfort's constable at Kenilworth, regrouped at the castle the following spring. Edward's forces proceeded to lay siege to the rebels.