There is much to be learned from the consideration of the positions of these fortresses. William’s first care, on obtaining possession of each district, was to order the preparation of such strong places as might be necessary for the holding of it. But it is evident that he was influenced also by another consideration: he desired to be regarded as the legitimate heir of the Confessor, rather than as the conqueror of the kingdom; and so far as was consistent with his own security, he strove to administer the ancient laws, and to leave the ancient tenures and private estates, and even English owners, undisturbed. This indeed, owing to the strong national discontent, shown by repeated insurrections and by a general current of ill-will of which these were the indications, he speedily found to be out of the question. But even while driving out the native magnates, he was careful to associate the new men, as far as possible, with the past, in the hope (well founded) that before long the “successores et antecessores,” as they are called in “Domesday,” would be looked upon as part of a continued line,—Earl Roger, for example, as the representative of Edwin of Shrewsbury, Hugh Lupus of Morcar, and William Fitz Osbern of Ralph the Earl of Hereford under the Confessor. And this policy is particularly evident in the sites of the castles. Where circumstances absolutely required it, an entirely new position was selected; but this was extremely rare, and probably did not occur in half a dozen instances, if indeed in more than London and Richmond. Usually it was found that the English lord had attached to his estate an earthwork upon which he and his ancestors had lived for centuries, which was identified with the estate or district, and regarded with respect and confidence by the surrounding tenantry. It is surprising to find how completely the leading positions in the country had thus been occupied. The upland passes; the margins of the rivers; the summits, where readily accessible, of the detached hills; the spots rendered strong by cliffs or ravines, or extended or impracticable marshes. Each had its _aula_, where a succession of lords had identified themselves with their people, afforded them protection, and received in return their support. Such were Guildford, Farnham, and Berkhampstede, in the clefts of the belt of chalk by which London is girdled; Hertford, Bedford, Wallingford, Tamworth, Worcester, Shrewsbury, Durham, and York, upon the banks of deep or rapid streams; Windsor, Belvoir, Lincoln, Corfe, and Montacute, placed on the summit of more or less detached hills, commanding a broad sweep of country; Dover, Scarborough, and Bamborough, upon rugged and lofty sea-cliffs, isolated by deep and formidable ravines; Huntingdon, Cambridge, Ely, and Oxford, more or less covered by marshy fens at that time almost impassable; while attached to and so placed as to overawe their adjacent cities or