castle, type of fortified dwelling characteristic of the Middle Ages. Fortification of towns had been in practice since antiquity, but in the 9th cent. feudal lords began to develop the private fortress-residence known as the castle. It served the twofold function of residence and fortress because of the conditions of medieval life, in which war was endemic. The site of the castle was preferably on a defensible height. England and France, in general, did not afford such inaccessible locations as did the Rhine valley in Germany.
The Early Castle
The castle of W Europe was a Norman creation, an outgrowth of the 10th- and 11th-century mound castle, which consisted of a great artificial mound of earth, the motte, surrounded by a dry ditch, or fosse, and surmounted by a wooden blockhouse and its encircling palisade. Until well into the 12th cent., the only English development was the occasional substitution of a massive masonry keep inside the palisade—a form typified in the Tower of London. As siegecraft (see siege) was evolved, provisions were made for an aggressive defense.
A castle that became the model for many English and Norman castles was the formidable castle built at Arques in Normandy by Henry I of England. A square donjon, or keep, was set against the strong outer walls of masonry; the entrance was protected by a double gate, two flanking round towers, and advanced earthworks. The place enclosed by the outer circuit of walls was usually divided into two courts, or baileys, by a palisade. Subterranean passages made detection of underground forays easy.
The Fully Developed Castle
In the Middle East the Crusaders developed great castles with double circuits of curving outer walls and towers or turrets to overlook all sections of the wall. The form of these castles had an influence throughout the Continent and the British Isles. Thus early in the 13th cent. the medieval castle, a mixture of Norman, English, and Byzantine elements, reached its full flower, as typified in the Château Gaillard on the Seine in France and in Alnwick and the Conisborough in England.
In general, the castle was planned for security; the living quarters were rude, poorly lighted, and without provisions for comfort. Typically, the keep contained the living quarters of the lord and his family, the rooms of state, and the prison cells. Two independent systems of walls, each a fortress in itself, extended around the keep; the sections of the walls were flanked by towers, usually round, and the principal entrance was protected by strong gate towers, the massive gateway, with its portcullis and drawbridge, and the barbican, or advanced outwork. The defenders operated from galleries at the tops of walls and from the flat roofs of towers, whose battlements were provided with recesses with flaring sides, called embrasures, and openings, or machicolations, for shooting and dropping missiles on the attackers. The fully developed castle was thus marked by successive series of defenses; the fall of the outer works did not necessarily mean the loss of the entire castle.
With the use of gunpowder and consequent perfection of artillery, the castle lost its military importance. The manor house replaced the castle as the residence of the wealthy landowner, but the architectural influence of the castle has persisted even to the present day, when crenelations and towers are still found in country houses and some urban structures.
See S. Toy, History of Fortification from 3000 BC to AD 1700 (1955); W. D. Simpson, Castles in Britain (1966); A. Weissmüller, Castles from the Heart of Spain (1967); W. Anderson, Castles of Europe from Charlemagne to the Renaissance (1971); P. Warner, The Medieval Castle (1972).