|either of two civil wars in 13th-century England. The First Barons' War (1215--17) was precipitated by King John's failure to observe the terms of Magna Carta: many of the Barons' grievances were removed by his death (1216) and peace was concluded in 1217. The Second Barons' War (1264--67) was caused by Henry III's refusal to accept limitations on his authority: the rebel Barons (led (1264--65) by Simon de Montfort), initially successful, were defeated at the battle of Evesham (1265); sporadic resistance continued until 1267|
(1264-67), in English history, the civil war caused by baronial opposition to the costly and inept policies of Henry III. The barons in 1258 had attempted to achieve reform by forcing Henry to abide by the Provisions of Oxford (see Oxford, Provisions of). When, by the Mise of Amiens (1264), the Provisions of Oxford were declared invalid by Louis IX of France, some barons, led by Simon de Montfort, took up arms and, in May 1264, captured the king at the Battle of Lewes in the southeastern Downs. From then until his death at the Battle of Evesham in August 1265, Simon de Montfort largely controlled England and made important administrative and parliamentary experiments. A settlement was achieved by the Dictum of Kenilworth (1266) and finally by the Statute of Marlborough (1267), which remedied some of the baronial grievances.
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