The Tigress of Forli: Renaissance Italy's Most Courageous and Notorious Countess, Caterina Riario Sforza de' Medici, by Elizabeth Lev;
Dividing the Spoils: The War for Alexander the Great's Empire, by Robin Waterfield; and
Maurice's Strategikon: Your Handbook of Byzantine Military Strategy, translated by George T. Dennis.
OK, I threw in the "Your" for Maurice's Strategikon. It just seemed to fit, though. I mean, who doesn't need to know about Byzantine military strategy, right? Anyway, this book was THE Bible of Eastern Roman tactics, written as it was by the Eastern Roman Emperor Maurice, and was actually intended for use by field commanders. It gives insight on how the workings of the late Roman and Eastern Roman military and how its officers were supposed to think.
Dividing the Spoils is part of my attempt to assemble a library of a rather undercovered period of history, the wars of the Diadochi.
If you have played the video games Assassin's Creed 2 or Assassin's Creed: Brotherhood, you've gotten a taste of Caterina Sforza, who is one of the main protagonists (and a very impressive protagonist at that, especially with her intelligence, drive and sharp tongue). Check out how the real life Caterina Sforza measures up to her video game counterpart.