Over one thousand castles were built in the century following the Norman Conquest. Most were constructed in the wake of the Conquest itself by the Norman lords and their allies as they took possession of their lands. A castle was a fortified feudal residence, a symbol of a lord's power and authority and the instrument of regional domination: administrative, judicial and military. Very few castles remain unaltered from when they were first built and none fits neatly into any particular category. Many have succumbed to the ravages of siege warfare, abandonment and despoliation, especially in the aftermath of the English Civil War. Some have been entirely rebuilt and most have been remodelled many times, according to the current military, domestic and architectural fashion. For several there is evidence of continuous occupation from the twelfth century to the present day. Stephen Friar has a encyclopedic knowledge of all aspects of castles as well as the ability to place issues within a historical context and explain them succinctly and clearly for the non-specialist. From quadrangular castles to shell keeps, garderobes and gargoyles to tournaments, and anarchy to zig-zag moulding, this detailed A to Z reference book, with its lavish illustrations, index of castles and lists of addresses and further reading, is essential for anyone interested in medieval castles.