I read this book because I figured it would be a pretty quick read, and it was.  I picked it up on impulse at the book store a couple of weeks ago.

From all that I have read, there is no historical proof that Henry II and the Princess Alais, Henry's son Richard's betrothed, had an affair, although it does seem to have been a contemporary rumor.
This book imagines that Henry and Alais did indeed have an affair, after Alais believes she is betrayed by the two people she loves the most in the world, Queen Eleanor who took her under her wing and taught her strength, and the Prince Richard, who loved her for herself, but who she found to be unfaithful.
This book does a good job of making Henry and Alais' affair real and passionate, even through Alais' guilt and confusion (she WAS only 15, afterall).  Eleanor is worldly and gracious, though always the cunning politician, and Richard is wounded to the quick by Alais' own betrayal of him.
In the end, this book was a good read, the story moved quickly and I was eager to see how the author would have the character's relationships play out.  I was pleased by the end results.
Good book, especially if you are curious about this princess of France who is often lost in all of the other Angevin family drama of the time.