It's a well-written book. The most startling claim made by Weir is that Edward II was not murdered, but escaped and retired from the world; some other poor soul was buried in his place. Now, there is some contemporary evidence that does, indeed, need to be taken into account, but still, I find the possibility of Edward II's escape and retirement extremely hard to believe. I can't see it within the character of the man, both as a king raised to power and status and as the vain, grasping man that we know him as. But at least she marshals some evidence for her conclusions, make of them what you will.
On the last page of her biography, however, is the almost-as-startling statement that Isabella is to be credited with "launching the sole successful invasion of England since the Norman Conquest." What does this make of William of Orange's invasion in the Glorious Revolution of 1688? Now, if she means the sole succesful invasion "up to that time," well, fine. Or has she simply forgotten William?