The reign of Henry III., 1216-1272, was long, and that prince was a munificent patron of art, and especially of architecture; nevertheless, and notwithstanding the internal dissensions of the period, the reign produced (excepting perhaps in South Wales) but few original castles, and those not remarkable for grandeur. The cause of this was that the country was already rather over-furnished with castles, so active had the Norman lords been during a century and a-half, and the positions of the existing castles being well chosen, and their keeps of a substantial character, it was found better to add to them, when space was needed, rather than construct new ones in new positions. The itinerary of John shows that almost all the great castles of the country were even then built, and the use to which they were so frequently put may well have made the successors of that sovereign anxious rather to destroy than to build. Thus Bedford, a very early and very strong castle, was held by Fulke de Bréauté against the king in person, and was only taken by assault after a vigorous siege of two months, after which it was not only dismantled, but destroyed, its ditches filled up, and the materials of its walls and towers used for other constructions. Sometimes, however, where it was desirable, as in London or at Porchester, or Winchester, or Richmond, to retain the existing castle, either _enceinte_ walls or more extended outworks were added, affording more accommodation for troops or for live stock for the garrison. Palisades gave place to walls, and mural towers and gatehouses, of large size and great strength, were added. Sometimes, as at the Tower of London, an outer ward, encircling the older building, was added; in other cases, as at Corfe, Chepstow, and Barnard Castle, the new ward was applied on one side, or at one end. In these augmented castles the keep was still treated as an interior citadel, a last resource or refuge, and was protected by one or two lines of wall, with mural towers, usually round or half round, and by gatehouses, composed of two round towers with the entrance between them, the new area within being proportioned to the importance of the place.