Notable rulers such as William the Conqueror, King John, Llywelyn ap Gruffudd and Edward I feature prominently as the builders and conquerors of castles.
Dramatic events such as the epic sieges of Rochester in 1215 and Kenilworth in 1266 are covered, as well as details of castle building, garrisoning and provisioning.
Changes in castle architecture, military technology and weaponry are traced, including the rise of gunpowder weapons. A wide range of chronicles, administrative sources, archaeological evidence and other historical research is used to bring the story of the castle at war to life.