Second Barons' War
约翰时期以First Barons' War终结。亨利三世时期，爆发了Second Barons' War。
The Second Barons' War (1264–1267) was a civil war in England between the forces of a number of barons led by Simon de Montfort against Royalist forces led by Prince Edward (later Edward I of England), in the name of Henry III.
The reign of Henry III is most remembered for the constitutional crisis in this period of civil strife, which was provoked ostensibly by Henry III's demands for extra finances, but which marked a more general dissatisfaction with Henry's methods of government on the part of the English barons, discontent which was exacerbated by widespread famine.
French-born Simon de Montfort, Earl of Leicester, had originally been one of the foreign upstarts so loathed by many lords as Henry's foreign councillors, but having inherited through his mother the English title Earl of Leicester, he married Henry’s sister Eleanor without Henry's permission, and without the agreement of the English Barons (ordinarily necessary since it was a matter of state). As a result, a feud developed between de Montfort and Henry. Their relationship reached a crisis in the 1250s, when de Montfort was put on trial for actions he took as lieutenant of Gascony, the last remaining Plantagenet lands across the English Channel.
Henry also became embroiled in funding a war against the Hohenstaufen Dynasty in Sicily on behalf of Pope Innocent IV in return for the Hohenstaufen title King of Sicily for his second son Edmund. This made many barons fearful that Henry was following in the footsteps of his father King John and, like him, needed to be kept in check. When Henry's treasury ran dry, Innocent withdrew the title, and in regranting it to Charles of Anjou in effect negated the sale.
（教皇英诺森四世许诺，让亨利三世的二子埃德蒙做西西里国王， 当然有条件， 前提是亨利三世帮教皇收拾西西里当政的德国霍亨斯多芬王朝。贵族们一听就急了，怕亨利步他老爸约翰后尘东征西讨，觉得有必要限制他的权力。后来等亨利把国库的钱都挥霍光了，教皇立马取消了空头支票，把西西里国王的头衔送给了Charles ofAnjou 安茹的查尔斯. 好一个唯利是图出尔反尔的教皇，呵呵。英格兰当时闹饥荒，亨利三世还征收军费打仗，好一个糊涂国王。贵族岂有不反之理？）
Simon de Montfort became leader of those who wanted to reassert the Magna Carta and force the king to surrender more power to the baronial council. In 1258, initiating the move toward reform, seven leading barons forced Henry to agree to the Provisions of Oxford, which effectively abolished the absolutist Anglo-Norman monarchy, giving power to a council of twenty-four barons to deal with the business of government and providing for a great council in the form of a parliament every three years, to monitor their performance.
every three years---根据Encyclopædia Britannica，应当是three times a year。 这段英文有点模糊，其实牛津条例是说由国王与议会共同治国，见后面转帖。 ）
Henry was forced to take part in the swearing of a collective oath to uphold the Provisions of Oxford. In the following years, those supporting de Montfort, including his circle of Franciscan advisors centered on Adam Marsh, and those loyal to the king grew more and more polarised; Henry obtained a papal bull in 1261 exempting him from his oath, and both sides began to raise armies, the Royalists under Edward Longshanks, Henry's eldest son. A civil war followed.