the town besiege the castle. John now tried to deceive him by forged letters. Fitzwalter, conscious of the weakness of his position, sought to negotiate. On 9 November, Fitzwalter received with the Earl of Hertford and the citizens of London safe conduct for a conference, but nothing came of it. In vain the beleaguered garrison of Rochester bitterly reproached him for deserting them. On 10 November they were forced to surrender. On 16 December the barons, including Fitzwalter, were excommunicated by name. French help was now their only refuge. Fitzwalter went over to France with the Earl of Winchester and offered the throne to Louis, the son of King Philip, putting into his hands twenty-four hostages and assuring him of the support of their party. Fitzwalter was back in England early in 1216. Louis landed in May, and as John made great progress in the east, Fitzwalter busied himself in compelling Essex and Suffolk, his own counties, to accept the foreign king. The tide of fortune now turned, but after John's death on 19 October Fitzwalter's difficulties increased. Gradually the English went over to the side of the new king Henry III. Those who remained in arms were not respected by the French, because of their betrayal of John. On 6 December Louis captured Hertford Castle from the followers of the new king Henry. Fitzwalter naturally asked for the custody of a stronghold that had already been so long under his care. The French urged that a traitor to his own lord was not to be trusted, and Louis told him he must wait until the end of the war. Fitzwalter was too deeply pledged to Louis to join the deserters. He was sent from London on 30 April 1217 at the head of a strong French force to raise the siege of Mountsorrel in Leicestershire, now closely pressed by the Earl of Chester. On his way he rested at St Albans, where his hungry troops ate up all the supplies of the abbey, according to abbey chronicler Matthew Paris. He raised the siege of Mountsorrel and advanced to Lincoln. He was met by the regent, William Marshall, whose forces were now joined by the Earl of Chester with the army that had besieged Mountsorrel. Fitzwalter was anxious for an immediate battle. On 20 May Fitzwalter fought in the Second Battle of Lincoln, in which the baronial forces were thoroughly