Seventeen years after King Edward's visit, William the Conqueror's messengers came before the chief men of Exeter demanding their submission. But the citizens sent back the lofty answer that 'they would acknowledge William as Emperor of Britain; they would not receive him as their immediate King. They would pay him the tribute which they had been used to pay to Kings of the English, but that should be all. They would swear no oaths to him; they would not receive him within their walls.' William naturally would not listen to conditions, and arrived to direct the siege in person. For eighteen days the repeated attacks of the Normans were sturdily resisted; then the enemy dug a mine, which caused the walls to crumble, and surrender was inevitable. 'The Red Mount of Exeter had been the stronghold of Briton, Roman, and Englishman;' under the hands of the Norman here rose the Castle of Rougemont, of which a tower, a gateway, and part of the walls, stand to this day. In proportion to the size and strength of that castle, however, the remains are inconsiderable, but it fell into decay very long ago, and as early as 1681 Izacke writes of 'the Fragments of the ancient Buildings ruinated, whereon time ... hath too much Tyrannized.' In the year after King Stephen began to reign, Baldwin de Redvers, Earl of Devon and keeper of the Castle, declared for the Empress Maud, and held the Castle for three months against the citizens, headed by two hundred knights who had been sent by the King. At the end of this time the wells ran dry, so that the besieged were driven to use wine for their cookery, and even to throw over their 'engines,' set on fire by the enemy.