I had the pleasure of walking into this book knowing very little about it. I know John M. "Mike" Ford mainly from his comments and occasional posts on Making Light, and this book was recommended somewhere or another (probably there). I managed to forget whatever was on the back cover and just dive in. And I had such a great time discovering the book on its own terms that I'm rather hesitant to tell you anything more.
I'll say this: it's a history, and a fantasy (but despite the title, not an elves-and-dwarves-and-dragons fantasy). It's got quite a bit of the complicated genealogy of Richard Plantagenet (later Richard III) that, quite frankly, often went over my head. And half of everyone seems to be named Richard or Edward. But it's also got some of the most vivid and gripping characters I've ever read.