LAUNCESTON, or Dunheved,[488] Cornwall (Fig. 19).--There, says Domesday Book, is the castle of the Earl of Mortain.[489] In another place it tells us that the earl gave two manors to the bishop of Exeter "for the exchange of the castle of Cornwall," another name for Dunheved Castle. We have already had occasion to note that the "exchange of the castle," in Domesday language, is an abbreviation for the exchange of the site of the castle. The fact that the land was obtained from the church is a proof that the castle was new, for it was not the custom of Saxon prelates thus to fortify themselves. The motte of Launceston is a knoll of natural rock, which has been scarped and heightened by art. This motte now carries a circular keep, which cannot be earlier than the 13th century.[490] There is no early Norman work whatever about the masonry of the castle, and the remarkably elaborate fortifications on the motte belong to a much later period.[491] The motte rises in one corner of a roughly rectangular bailey, which covers 3 acres. It stands outside the town walls, which still exist, and join those of the castle, as at Totnes. Launceston was only a small manor of ten ploughs in the time of the Confessor. In spite of the building of the castle, the value of the manor had greatly gone down in William's time.[492] The ten ploughs had been reduced to five. [Illustration: FIG. 19. Launceston, Cornwall. Lewes, Sussex.] LEWES, Sussex (Fig. 19).--The castle of Lewes is not mentioned in its proper place in Sussex by Domesday Book, and this is another proof that the Survey contains no inventory of castles; for that the castle was existing at that date is rendered certain by the numerous allusions in the Norfolk portion to "the exchange of the castle of Lewes."[493] It is clear that at some period, possibly during the revolt of Robert Curthose in 1079, William I. gave large estates in Norfolk to his trusty servant, William de Warenne, in exchange for the important castle of Lewes, which he may have preferred to keep in his own hands at that critical period. This bargain cannot have held long, at least as regards the castle, which continued to belong to the Warenne family for many generations. We cannot even guess now how the matter was settled, but the lands in Norfolk certainly remained in the hands of the Warennes.