The manor had evolved as an effective response to the economic disruption of post-Roman Europe, but the military dangers of the medieval world required solutions on a larger scale. Although the manor lord might be able to turn out a levy of his tenants in an emergency, they were poorly equipped, unused to combat, and not necessarily very useful in a fight. His own household probably included a few better equipped soldiers, he himself might well have had the training and equipment of a knight, and his manor might have been protected by some light fortifications, but none of this would do much good in the face of a serious military force.
The military threat was always very real. Raiding was common in border regions, and even in the heart of a fairly stable kingdom, civil strife could arise at any time in an age when central government was weak, the political structure founded on fluctuating personal relationships, and society ruled by a class whose avowed function in life was warfare. War was still an exceptional event in most people's lives, but it was common enough that local military preparedness was essential. Effective response to the military challenges of the medieval world required the power of a great lord able to command a substantial following of local knights, and by the High Middle Ages, the castle had arisen as the distinctive seat of a great feudal lord's power.
This chapter will explore the castle as it represents the world of the feudal aristocracy, using the example of Dover Castle, at the southeastern tip of England. Dover was in many ways exceptional, for it was among