There was a Mowbray Castle at Epworth, now destroyed, and one at Kenefar, laid level by Henry, Bishop of Lincoln, in the reign of Henry II. Bourne or Brun was in 870 the seat of a Saxon Thane, whose mound, after the Conquest, was occupied by the Lords Wake. It was at one time an important place, and the remaining earthworks show its area to have been considerable. Bolingbroke Castle, once the “caput” of an Honour, is now destroyed. Stamford-on-the-Welland was guarded by two mounds, thrown up in 922, of which one has disappeared, but the other, as at Bedford and Buckingham, was saved by its incorporation into a Norman castle, to be seen no longer. Sleaford, an episcopal castle, occasionally mentioned in the twelfth century, is now gone, as is the castle of Horncastle, restored to Adelais de Condie in 1151, but at the same time ordered to be demolished, and which probably stood within the walls of the Roman station, of which large fragments remain. Bitham also is gone, taken by siege and levelled by Henry III. in 1218. Folkingham, the “Mansio capitalis” of Ulf the constable, was held by Gilbert de Garod, and long afterwards fell to the Lords Beaumont. Boothby was a fortified house of the Paynells or Paganels, and is of late Norman date. Topclyve Castle was built by Geoffrey, bishop-elect of Lincoln, in 1174. CHAPTER VII. THE CASTLES OF ENGLAND AND WALES AT THE LATTER PART OF THE TWELFTH CENTURY (_continued_). The castles of the shires of Nottingham and Derby, of Yorkshire, Lancashire, and Cheshire, complete the tale of the fortresses south of the Tees and Lune. Nottingham, one of the castles ordered and possibly built by the Conqueror, on a rock high above the Trent, contained one of the grandest of the rectangular keeps. It was removed in the seventeenth century, and replaced by a building of about the same dimensions, but of very different character. At the foot of the rock were the two mounds thrown up in the tenth century to command the passage of the Trent, but these also have been removed. Another castle upon the Trent was that of Newark, the work of Alexander, Bishop of Lincoln, in the twelfth century. The very considerable remains include the front towards the river, an imposing mass of masonry, the effect of which is heightened by the great gatehouse upon its flank, a Norman work of very unusual size and splendour. The ground plan of this castle is nearly square, and may represent a Roman encampment. There was a castle at Worksop.