Tunbridge castle, which was held for Odo, was first stormed, and on the news of this Odo thought it prudent to betake himself to Pevensey, where his brother, Robert of Mortain, was, and where reinforcements from Robert of Normandy would be likely to land. William at once turned from his march to Rochester and began the siege of Pevensey. The Norman reinforcements which Robert finally sent were driven back with great loss, and after some weeks Pevensey was compelled to surrender. Bishop Odo agreed to secure the surrender of Rochester, and then to retire from England, only to return if the king should send for him. But William unwisely sent him on to Rochester with a small advance detachment, to occupy the castle, while he himself followed more slowly with the main body. The castle refused to surrender. Odo's expression of face made known his real wishes, and was more convincing than his words. A sudden sally of the garrison overpowered his guards, and the bishop was carried into the castle to try the fortune of a siege once more. For this siege the king again appealed to the country and called for the help of all under the old Saxon penalty of the disgraceful name of "nithing." The defenders of the castle suffered greatly from the blockade, and were soon compelled to yield upon such terms as the king pleased, who was with difficulty persuaded to give up his first idea of sending them all to the gallows. The monk Orderic Vitalis, who wrote an account of these events a generation after they occurred, was struck with one characteristic of this insurrection, which the careful observer of any time would hardly fail to notice. He says: "The rebels, although they were so many and abundantly furnished with arms and supplies, did not dare to join battle with the king in his kingdom." It was an age, to be sure, when wars were decided less by fighting in the open field than by the siege and defence of castles; and yet the collapse of so formidable an insurrection as this, after no resistance at all in proportion to its apparent fighting strength, is surely a significant fact. To notice here but one inference from it, it means that no one questioned the title of William Rufus to the throne while he was in possession. Though he might be a younger son, not elected, but appointed by his father, and put into the kingship by the act of the primate alone, he was, to the rebellious barons as to his own supporters, the rightful king of England till he could be overthrown.