Just finished Julian: Rome's Last Pagan Emperor. Unfortunately, didn't learn anything I didn't already know.
Starting Greek Fire, Poison Arrows, and Scorpion Bombs: Biological and Chemical Warfare in the Ancient World. Two chapters in and I'm already finding it very enlightening!
I've received several complaints about this. Whatever your opinions on non-sexualized nudity, it would be appreciated if you marked it NSFW simply to avoid the issue.