Why is Robert Bruce a giant? Because he proved to the medieval world that superior military might could be overcome even in battle by a well-disciplined, tactically innovative and brilliantly led force. Because his approach to warfare gave food for thought to many on the opposing side, and helped to inspire the evolution of English military tactics over the following century, contributing to their extraordinary performance during the Hundred Years war with France. Because the difficult circumstances of his reign, both internally and externally, helped to produce a more coherent and uniform expression of Scottish national identity, contributing to the development of such ideas more generally. This is the story of the revolutionary medieval Scottish king, renowned across Christendom as a great and innovative warrior.