The castle is a unique phenomenon. Most buildings are created to fulfill a single, specific purpose like a church, a house, a factory, a school, etc. A castle could be a military base, a seat of government, a court, and a stronghold for the surrounding region. Castles have fascinated generations of people even after they outlived their usefulness. Their remains still put people in awe today. The design of medieval castles in England changed during 1000-1500 as the castle developed into the most important defense asset in war and politics only to become outdated.
             Castles were the product of that period of history termed the Middle Ages. Feudalism is the name applied to the military society which was created in Europe during the 9th and 10th centuries AD and reached its most developed form in Normandy in the 11th century. Feudal society resembled a pyramid. At its apex was the king who owned all the land in his kingdom (Platt 2). Immediately below the king was a group of major landholders who held their land directly from him, his tenants-in-chief. These were the great lords and magnates of the kingdom. In return for their land, they swore to give the king military service; that is, they and their retainers would fight for the king whenever and wherever he chose. The tenants-in-chief let out land to their tenants, the lesser barons and lords, on the same terms. This process was repeated all the way down the pyramid to the knight who was the local lord of the manor.
             The amount of land a man held was directly proportional to the amount of military service he could render (Platt 1). A knight might only be liable to appear at the muster with a horse, his weapons, a suit of chain mail and one or two servants as men-at-arms. A tenant-in-chief would be expected to provide scores of knights and several hundred men-at-arms. This decentralization of land-holding and power required that each landholder provide himself with a base from wh...