Clash of Crowns by Mary McAuliffe (nonfiction)

A Story of Bloodshed, Betrayal and Revenge - The Clash of Crowns:  William the Conqueror, Richard Lionheart, and Eleanor of Aquitaine.  Super long title, pretty zippy read.  I've read about all three of these folks quite a bit, and I found this book interesting because of the geography-based analysis of the battles between Richard of England and Phillip of France, which is what most of the book is about.  The author has obviously spent a lot of time traveling and researching in the area, and that adds to her ability to explain events.