The legate’s interference put enormous pressure on the English prelates who had thrown in their lot with Montfort. With the threat of excommunication hanging over their heads, they went back and forth across the channel with overtures for a permanent settlement, but to no avail. The legate was still implacably hostile when he was forced to return to Rome upon the death of the pope in October. Elected the new pope, he continued his rant against Simon from the Holy See, calling him and his family “pestilence”. In an effort to demonstrate their independence, the bishops demanded and received redress for the losses they had incurred during the war, some of it notably at the hands of Gilbert de Clare. His men had wreaked havoc wherever they went, including slaughtering the Jews of Canterbury. The royalists had been equally depraved in their march through farms and hamlets, and the widespread disorder posed the greatest threat to the provisional government. Henry had always made it a point of pride that England enjoyed nearly fifty years of peace under his rule. Now he was a captive, reluctantly putting his seal to the decrees and ordinances placed before him as Montfort attempted to stabilize the situation. But the majority of magnates, none too pleased at being dictated to by one of their own, remained aloof or hostile. Clare grew disaffected when Simon thwarted his claim to Richard as a hostage, and more so when his insistence on Edward’s release was vetoed. He especially looked amiss at all the power and property Simon was concentrating in the hands of his family. Gilbert felt cheated out of the spoils, and slighted that he, the earl of Gloucester, should be marginalized in favor of the Montfort sons. “It’s ridiculous,” Clare declared, “that this alien should presume to subjugate the whole kingdom.” By reminding one and all that the government was in the hands of an alien, who he claimed was garrisoning royal castles with other aliens, Gilbert was attempting to promote himself as the true defender of the Provisions.
A truce was to be observed during the course of arbitration. Henry being Henry, he ordered Roger Mortimer, an exceedingly violent man even for a marcher baron, to attack Simon’s manors in the hope of preventing his adversary from attending the proceedings in person. He knew the reformist side hinged on Montfort’s powers of persuasion and his friendship with Louis. In the end, all it took was a hole in the ground. While heading south for Dover, Montfort suffered a broken leg when his horse stumbled and fell. Forced to stay behind, he was no doubt confident the king of France would still rule close to his original affirmation of the Provisions. Louis, however, stunned everyone by completely nullifying them in his Mise of Amiens issued on 23 January 1264. Acting “unmindful of his own honour,” in the words of one chronicler, he declared that Henry had the right to appoint any official he saw fit, whether native-born or not. He tried to evade responsibility by insisting that the pope had nullified the Provisions first, then hedged by assuring the people of England that Magna Carta was in no way affected by his ruling. Sworn to abide by the award, Simon and his associates justified their continuing resistance by arguing that the Provisions were founded on the principles of Magna Carta. Louis’ betrayal, which was variously attributed to bribes, nagging or some concerted action with the papacy, rankled deeply. “Though all may forswear me, I will stand firm with my sons in the just cause to which my faith is pledged,” Simon proclaimed, adding gloomily that of all the lands he had been to, never had he met with more treachery than in England. But he did get some help when Gilbert de Clare finally decided to join forces with him and London remained firmly committed to the reformist cause. Civil war was now inevitable.
Edward was the first to return. Scolded by his father for “indolence and wantoness” while the Welsh ravaged the marches, he landed with a large mercenary force of Burgundians and other French-speaking soldiers. His jilted retainers had half-expected him to take them back into his service, but he completely ignored them and bestowed castles and other key posts on his new, alien followers. Incensed, they welcomed Simon de Montfort home as the one leader who had always been faithful to the Provisions, who was capable of enforcing the one provision they desired above all else: expulsion of the aliens. It was, of course, the great irony of this conflict that the English would turn to an alien for this purpose. Simon’s military reputation and unwavering defense of the Provisions made him the undisputed leader of this rebellious force that gathered in Oxford, where the reform program had been launched five years earlier. New adherents included many younger members of the baronage, among them Henry’s nephew Henry of Almain and the new earl of Gloucester, Gilbert de Clare, men later decried for being pliable as wax in the hands of a man like Montfort. He would need such idealists to offset the violence and unruliness of the Edwardians, who immediately went to work after Henry rebuffed one last call to observe the Provisions. They struck east, targeting the Savoyards and other aliens, even making knowledge of English a prerequisite to avoid reprisals. Locals long fed up with nobles, knights and clergymen who couldn’t speak their language joined in the mayhem until Henry found himself faced with a full-scale uprising. Richard rode off to intercede with Simon, but missed him on his march to secure the coast and trap Henry in London. But even that city was lost after Edward, needing money to pay off his mercenaries, staged the first great bank robbery in English history when he broke into the New Temple and seized the private deposits there. His mother grew sufficiently alarmed by the growing hostility to try to flee to Windsor by boat, but her barge was turned back after being pummeled with all manner of filth and flying objects thrown at her by a jeering crowd on London Bridge. She and her kinsmen eventually escaped to the continent, but for Henry it was all too much. He agreed to the restraints on his power enacted in 1258 and to the council naming his officials and conducting official policy. The only difference was the council was now controlled by Simon de Montfort.
When the two sides could not agree on any amendments to the Provisions, the arbitrator, Richard of Cornwall, ruled in favor of his brother and restored to him the sole right to appoint and dismiss officials. Henry would continue to rule with a packed court and the death of the earl of Gloucester in the summer of 1262 left the baronage without a nominal leader. Emboldened by events, the king sailed to France to meet his antagonist in court, where he hoped to destroy Montfort, at least in the eyes of the French. Queen Margaret was the arbitrator now, a dowdy woman who once looked amiss at all the attention Henry was paying to his niece Alice. She no doubt considered the vindictiveness of both sides unseemly, but her chance to rule on the case was interrupted when Henry was laid low by dysentery. Simon returned for the October parliament, where contrary to the order of the justiciar, he published his own papal bull, acquired through a baronial agent in Rome, affirming the Provisions. But a new threat arose to Henry’s consolidation of power, this time involving an alienated group of young men not connected to Montfort. They included Edward’s former retainers, proscribed by the queen and her Savoyard relatives in an attempt to tighten control over the heir, and Gilbert de Clare, Alice’s husband, who was supposed to succeed his father as the earl of Gloucester, only Henry, now in a completely vindictive mood, moved to deny him at least part of his inheritance. On top of this came another uprising by the Welsh, brought about when the tenants of Roger Mortimer, one of the barons cowed back into the royalist camp, revolted against his harsh rule. Local opposition also began to surge, forcing Henry to publicly proclaim that he accepted the Provisions by his own free will. The situation became so fraught that Henry, after his return home for Christmas 1262, wrote to Louis, begging him to find a successful resolution to his arbitration with Simon. Louis reported that Simon had told him that he truly believed Henry wished him only the best, but his advisers thought otherwise. He had therefore asked Louis not to concern himself any more with their case. He was preparing to return to England to have it out with the king once and for all.
In January, two years after he was elected King of the Romans, Richard prepared to return home. The barons were apprehensive about this most unexpected visit and sent messengers to him in Germany demanding he take the oath to observe the Provisions before landing in Dover. Richard was indignant that the magnates had instituted reforms without consulting him and therefore refused. Hearing this, and fearing that he may try to sneak one or more of his half-brothers into the kingdom, the magnates insisted on welcoming Richard with a force of arms. The King of the Romans disembarked with no Lusignans and willingly followed his brother the king and the magnates to Canterbury, where Richard de Clare, the earl of Gloucester and Richard’s former stepson, delivered the oath. The occasion marked the last complete show of unity among the barons. The next month a quarrel broke out over the progress of reform. Gloucester was in no hurry to see the new statutes apply to him or the other magnates directly, and besides he had no personal quarrel with the king. Only a few years before Henry had done him the honor of marrying his seventeen-year-old niece Alice, daughter of his now deceased half-brother Hugh Lusignan, to de Clare’s ten-year-old son Gilbert. Simon accused Gloucester of reneging on reform, and he in turn accused Montfort of delaying the peace treaty for his own benefit. When Simon left for France, saying he had had enough of his shady partner, the other magnates warned Gloucester to clean up his own domains, otherwise they would join forces and attack him. This he agreed to do, but it was the beginning of a feud between the Montfort and Clare clans that would determine the entire course of the conflict.