Historian Ruth Goodman and archaeologists Peter Ginn and Tom Pinfold turn the clock back as they learn how to build a medieval castle using the same tools, techniques and materials available in the 13th century. This time the team are defending the castle. Ruth, Tom and Peter explore the art of medieval combat and the building of the castle's defensive structures. The 13th century was part of the 'golden age of castle building'. Driven by the legacy of bloody crusades and vicious dynastic struggles, it was an era when castle design and architecture were adapting as quickly as the battle strategies and tactics devised to bring them down. The team look at the ingenious features medieval castle builders came up with to withstand attack from an ever more formidable array of 'siege engines'.