From their earliest inception as places to withstand attack, to their heyday as grim reminders of an occupying power, castles and strongholds attest both to our insecurities and to our rapacious need for conquest. The author examines their development - as homes and at war, their building and their demolition - from neolithic strongholds to the "folie de grandeurs" of the last century. In between comes a voyage from Iron Age hill-forts and Roman defences, Saxon strongholds and the Norman invasion to the perfection of castle design in the Middle Ages.