In 1230 the last de Braose of Brecon, William de Braose was hanged by Prince Llywelyn ab Iorwerth and Brecon lordship with Hay-on-Wye passed into the hands of the de Bohuns. Taking advantage of this in 1231, Prince Llywelyn ravaged the lands of his de Bohun in-laws during which Hay-on-Wye town was burnt, although the castle survived the onslaught. The castle saw service in the Barons' War of 1263 to 1266, changing hands three times, once being surrendered to the great Simon de Montfort, 6th Earl of Leicester. With the conquest of Wales by King Edward I Longshanks life became more peaceful in this Marcher town.