Toward the end of July Philip despatched Arthur, with a force of two hundred French knights, to join the Lusignans in an attack on Poitou. The barons of Brittany and of Berry had been summoned to meet him at Tours, but the only allies who did meet him there were three of the Lusignans and Savaric de Mauleon, with some three hundred knights. Overruling the caution of the boy-duke, who wished to wait for reinforcements from his own duchy, the impetuous southerners urged an immediate attack upon Mirebeau, their object being to capture Queen Eleanor,[33] who was known to be there, and whom they rightly regarded as the mainstay of John’s power in Aquitaine. Eleanor, however, became aware of their project in time to despatch a letter to her son, begging him to come to her rescue. He was already moving southward when her courier met him on July 30th as he was approaching Le Mans. By marching day and night he and his troops covered the whole distance between Le Mans and Mirebeau—eighty miles at the least—in forty-eight hours, and appeared on August 1, 1202, before the besieged castle. The enemies had already taken the outer ward and thrown down all the gates save one, deeming their own valor a sufficient safeguard against John’s expected attack. So great was their self-confidence that they even marched out to meet him. Like most of those who at one time or another fought against John, they underrated the latent capacities of their adversary. They were driven back into the castle, hotly pursued by his troops, who under the guidance of William des Roches forced their way in after the fugitives, and were in a short time masters of the place. The whole of the French and Poitevin forces were either slain or captured; and among the prisoners were the three Lusignans and Arthur.
Philip was at that moment busy with the siege of Arques; on the receipt of these tidings he left it and turned southward, but he failed, or perhaps did not attempt, to intercept John, who, bringing his prisoners with him, made his way leisurely back to Falaise. There he imprisoned Arthur in the castle, and despatched his victorious troops against Arthur’s duchy; they captured Dol and Fougeres, and harried the country as far as Rennes. Philip, after ravaging Touraine, fired the city of Tours and took the citadel; immediately afterward he withdrew to his own territories, as by that time John was again at Chinon. As soon as Philip was gone, John, in his turn, entered Tours and wrested the citadel from the French garrison left there by his rival; but his success was won at the cost of another conflagration, which, an English chronicler declares, was never forgiven him by the citizens and the barons of Touraine.