Simon de Montfort and his friends were put in an awkward position by this decision, to which they had so unwisely committed themselves. But they did not hesitate to declare that they must repudiate the mise. Simon declared that it would be a worse perjury to abandon his oath to keep the Provisions of Oxford than his oath to abide by the French king's award. He took arms again at the head of the Londoners and his personal adherents and allies. But many of the barons stood neutral, not seeing how they could refuse to accept the arbitration they had courted, while a number not inconsiderable joined the king, deciding that Leicester had passed the limits of reasonable loyalty, and that their first duty was to the crown. The barons' war: battle of Lewes. Hence it came to pass that in the campaign of 1264 Simon was supported by a minority only of the baronial class, and the king's army was the larger. The fortune of war inclined at first in favour of the royalists, who captured Northampton and Nottingham. But when it came to open battle, the military skill of the earl sufficed to compensate for the inferiority of his numbers. At Lewes, on the 14th of May, he inflicted a crushing defeat on the king's army. Henry himself, his brother Richard of Cornwall, and many hundreds of his chief supporters were taken prisoners. His son Prince Edward, who had been victorious on his own flank of the battle, and had not been caught in the rout, gave himself up next morning, wishing to share his father's fate, and not to prolong a civil war which seemed to have become hopeless. Montfort's parliament.