From its origin to its decline. Why did castles come into being, why were there so many different types of construction and what made these tried and tested defences redundant after many thousands of years? These and many other questions are explored. For example, the reader learns that the origins of the castle date back to the Neolithic period and that its structural design was constantly improved from antiquity to the Middle Ages, until the castle finally disappeared at the beginning of the early modern period. Characteristic examples are used to present castle types and individual famous castles.