The Devil's Queen by Jeanne Kalogridis

This is the first novel I've read based on the life of Catherine de Medici.  I'm a little embarrassed to say that I knew very little about her.  I've read a lot more English history than Italian and my French history centers more around the French Revolution than the age of Reformation.  The only thing I really knew about Catherine de Medici prior was that her family had a part in raising Mary, Queen of Scots. 
I found this book fascinating.  It is very bloody (but that part of history was) and there is a lot of belief in the dark arts (which she did partake in).  Beyond that, I don't know how much was fact and how much was fiction.  As with many historical novels this one prompted me to do my own little bit of research on the character and those around her.  One of the main characters of this book is someone whom very little is known about, Cosimo Ruggieri.  As well, one of Catherine's sons is missing from the book.
I was expecting a real hard hearted, difficult woman.  What I found was a sympathetic character, a pawn in her family's need for power.  I would be interested in reading more of this woman and this era and see how other authors have put their own spin on it.  Any suggestions?