Malcolm Hislop is a buildings archaeologist and author with a special interest in medieval buildings. His doctoral thesis was based around the career of the Durham master mason, John Lewyn, one of the most prolific castle builders of the fourteenth century, and he has continued to maintain a keen interest in the process of medieval building design and construction. He is the author of John Lewyn of Durham, How to Build a Cathedral and How to Read Castles. Born in Yorkshire, he now lives in north-east Wales.