The Norman castles were of great strength, though not always built of stone. Many were built on the sites of British encampments or Saxon 'burhs', in which case the old wooden stockade was doubtless allowed to remain. The central fortress or keep, a square, or sometimes circular, building with walls of immense thickness, was surrounded by an inner ward or courtyard in which cattle and provisions could be gathered in case of attack, and where, on a raised mound in the centre, the baron held his court. Round this ward were grouped the domestic apartments, the stables, and the quarters of servants and retainers. Beyond these buildings was a second or outer ward, the whole being enclosed by walls with projecting towers at intervals. The castles of the plain were further protected, as at Aldford, by a deep ditch or moat crossed by a drawbridge leading to the principal entrance. The keep was the last place of refuge when the defenders were driven from the walls, and frequently contained a well of water. In the keep at Beeston Castle is a well over three hundred feet deep, to which water was perhaps at one time drawn from Beeston Brook or some other neighbouring stream. On the summit of Halton Hill you may still see a portion of the outer wall of the castle built by Nigel, Baron of Halton and cousin of Earl Hugh. He was the chief of all the Cheshire barons, was constable of the city of Chester, and led the Cheshire army, when required, against the Welsh. Thirty-seven manors, among them those of Congleton, Great Barrow, Raby and Sale in the county of Cheshire, were included in his possessions. Other barons created by the Earl of Chester were William of Nantwich, Vernon of Shipbroke, Fitzhugh of Malpas, Venables of Kinderton, Hamon Massi of Dunham, Nicholas of Stockport, and Robert of Montalt or Mold. The last-named shows that the county of Flint was at that time part of the earldom. The name of the Norman baron was often added to that of the Saxon village where he dwelt, as in the case of Dunham Massey, Minshull Vernon. The earl himself resided at Chester, where large additions were made to the stronghold of Ethelfleda, but probably his castle was built largely of timber, for no stone of it remains, and a hundred and fifty years later Henry the Third ordered the stockade with which the castle ward was enclosed to be removed and replaced by a wall of stone. On the eastern side of the castle was erected a great shire hall where the earl held his parliament, and an exchequer court where the dues and taxes were paid to him.