An agreement between Llywelyn ap Gruffydd and Simon de Montfort, the baronial leader who had Henry III in custody. On 19 June Llywelyn capitalized on civil war in England to secure advantageous terms from the barons, consolidating his control of the central marches of Wales. Although Simon was soon dead at Evesham (4 August), Henry III concluded a similar peace with Llywelyn at Montgomery (25 September 1267), confirming his title and status of prince, and his right to the allegiance of Welsh nobles. Llywelyn's power was at its height.
Subjects: British History.