First was Osprey Fortress #76: Saracen Strongholds AD 630 – 1050: The Middle East and Central Asia, which deals with the fortifications in Western and southern Asia from before the arrival of Islam into the time of the Crusades. I especially liked the chapter (section?) on caravanserai. Not bad.
Next was Osprey Elite #196: Napoleonic Light Cavalry Tactics, a very vital part of the armed forces of the period. Used for security of armies as well as scouting missions. I found this book fascinating.
Finally, Osprey Campaign #195: Syracuse 415- 413 BC: Destruction of the Athenian Imperial Fleet, an enormous mistake upon the part of Athens; one democracy against another. Sad for Athens, a proud victory for Sicily.