The Mise of Lewes was a settlement made on 14 May 1264 between King Henry III of England and his rebellious barons, led by Simon de Montfort. The settlement was made on the day of the Battle of Lewes, one of the two major battles of the Second Barons' War. The conflict between king and magnates was caused by dissatisfaction with the influence of foreigners at court and Henry's high level and new methods of taxation. In 1258 Henry was forced to accept the Provisions of Oxford, which essentially left royal government in the hands of a council of magnates, but this document went through a long series of revocations and reinstatements. In 1263, as the country was on the brink of civil war, the two parties agreed to submit the matter to arbitration by the French king Louis IX. Louis was a firm believer in the royal prerogative, and decided clearly in favour of Henry. The outcome was unacceptable for the rebellious barons, and war between the two parties broke out almost immediately.