Finished reading this some time ago. It was recommended by a historian friend with a special interest in Arthur.

This is an interesting read if you’re curious about the reality of King Arthur. The book discuesses the historical figure[s] and events that form the basis for the legend of King Arthur. There’s a ton of historical and archeological references and a good deal of something that feels like historical detective-work, showing that King Arthur, his knights of the round table and even Merlin are more than just fictional characters.