ABSTRACT
All the elements of scientific fortification evolved steadily throughout the thirteenth century, reaching at its end their highest English development in the great building campaigns of Edward I in North Wales. This is justly considered the zenith of English castle-building, after which no such glories were to appear again; in the shadow of its grandeur, the greater part of the fourteenth century is frequently seen as a period of decadence and decline. Indeed, compared with this great programme of royal castle-building and the massive surge of baronial construction on the part of the Marchers that accompanied it, not only the ensuing period, but also the earlier thirteenth century, inevitably looks unimposing. Baileys were comparatively tractable; the curvilinear plan, with possibly a certain amount of engineering, could be turned into some sort of polygon. King Edward and his masons were inclined to vacillate between the traditional form of concentric defence and the novel plan of Caerphilly type.
