When, in 1068, the Conqueror marched from York to Cambridge, he paused at Lincoln, even then a very important place, fenced in and populous, not indeed as yet boasting a minster, but numbering 1,150 inhabited houses, a leading member of the famous Danish civic confederation, and governed by twelve lawmen, who wielded powers elsewhere exercised by the territorial lords. As he traversed the intrenchment that covered the northern front, and entered the city through the strong Roman gateway, still in use, he could not but appreciate the strength and importance of the place, of which he seems to have been allowed to take peaceable possession. Here, as at York and Cambridge, he at once ordered the English stronghold to be converted into a Norman castle. What was the precise condition of the existing work, or what was immediately executed in obedience to William’s order, we do not know; there were, of course, defences, probably of timber, along the crest of the banks, and upon the summit of the mound, but whether William merely directed these to be strengthened, or had them replaced by walls such as were coming into use in Normandy, does not appear; probably the former: as time pressed, and there was much work of the same kind to execute all over England, it was important to secure an immediate shelter for the Norman garrison. That the 166 houses which, we learn from Domesday, were destroyed to make way for Lincoln Castle were not removed to allow of the extension of its area is certain, for the Norman walls stand upon the English banks. It is probable that, during the long and prosperous reign of the Confessor, houses had been allowed to be built upon the slopes and glacis of the ditch, and, perhaps, actually within the fortress. This, of course, could not be tolerated, and is probably the removal recorded. But, if timber was employed, it was, of course, only until works in masonry could be erected, and, whatever the Conqueror’s officers may have actually executed, there can be little doubt but that they or their immediate successors designed the gates, walls, and keep of the castles, as these now stand.