Excellent visual guide to how soldiers have fought through the ages. Of particular interest is a description of rations and items carried by individuals - military issue and personnel. I cab tell you that when you are in the military you tend to try to stock up on things (beef jerky/nuts for snacks) because you are never sure when you will be able to get what you need.
For what it is--a short photograph book with pictures of soldiers in Rome and in discrete wars from 900 to WW2--this is a pretty good book. It's like a DK book but not by DK. Its sole focus is what a run-of-the-mill soldier looked like, how he was equipped, what he ate, and how he fought. WWI and WWII are more extensively covered. Some wars show several classes of soldiers.
As a visual reference, this is a good starting point. There's a little history and there are a couple of explanations for special marks on uniforms. Each soldier has a name and a short story about how or why he joined the army.
My favorite thing I saw was a step-by-step sidebar of how full metal armor is put on. I also enjoyed seeing uniforms from many nations, especially WWI.