King Arthur has fascinated the Western world for over a thousand years and yet we still know nothing more about him now than we did then. Layer upon layer of heroics and exploits has been piled upon him to the point where history, legend and myth have become hopelessly entangled.

In recent years, there has been a sort of scholarly consensus that 'the once and future king' was clearly some sort of Romano-British warlord, heroically stemming the tide of wave after wave of Saxon invaders after the end of Roman rule. But surprisingly, and no matter how much we enjoy this narrative, there is actually next-to-nothing solid to support this theory except the wishful thinking of understandably bitter contemporaries.

Arthur: Shadow of a God gives a fascinating overview of Britain's lost hero and casts a light over an often-overlooked and somewhat inconvenient truth; Arthur was almost certainly not a...