Fortified building or group of buildings, characteristic of medieval Europe. The castle was originally designed as a defensive fortification, but it also functioned as a residence for the royalty and nobility, an administrative centre, and a place of safety for local people in times of invasion. In England castles were always designed as a fortified home. In 13th-century Wales, Edward I built a string of castles as military centres to keep control of the country. The castle underwent many changes, its size, design, and construction being largely determined by changes in siege tactics and the development of artillery. Outstanding examples are the 12th-century Krak des Chevaliers, Syria (built by crusaders); the 13th-century Caernarfon Castle, Wales; and the 15th-century Manzanares el Real, Spain. Structure Although there was no such thing as a typical castle throughout the era of castle-building, by the 12 th century certain features began to appear more frequently. These might include…