I purchased a copy of this book for my father about ten years ago. He was an instant fan, and he would often tell me about what a pleasure it was to read each chapter. He liked to savor them for fear of running out. I concur. Paul K. Davis is an excellent writer, weaving together history, war, politics, and culture. The real emphasis is on the last, as these decisive battles are generally discussed more in terms of the cultural and social significance than in terms of combat. Davis does go into a fair amount of tactics, strategy, arms, battle formations, and the like, but it's more to set the stage than the main event. The battles range across thousands of years and nearly every corner of the Earth.
There is one chapter for each of the hundred battles. Each chapter is only a few pages and is is a self-contained story, so you can conveniently flip to whatever battle interests you. I'm just writing this review today, but I've probably read this book five times over, just never cover-to-cover. This makes it accessible to a casual reader that is only interested in one or two battles At the same time, it's more than a survey text with each chapter having enough detail (and such excellent prose!) to satisfy a serious interest in the history of war. Davis uses a three part structure for each chapter: "Historical Setting" to put it in context, "The Battle" for what happened, and "Results" for the historical, political, and social consequences (essentially, why it's important). There are a fair number of illustrations, maps, battle formations, paintings, and brief side stories all to flesh out the text. The side stories typically take up half a page and range from further explanation of matters from the text (What was Greek Fire? Who were the Mamluks?) to additional background information (Emperor Justinian repeated forcing Belisarius into retirement for fear of his popularity, only to call on him again and again) or why one battle was included in the text in place of another (Moscow instead of Stalingrad).
You may think this book is geared toward aficionados of military history, but I honestly feel this book is best suited for a reader that is generally put off by the topic. That's not to say it's designed for conversion. But I feel military history is too often pigeonholed into a separate category, something interesting and valuable only to people that like fighting and war. This criticism often comes in the form of "a bunch of names and dates", and indeed many people do learn history as learning a list of things that happened and when they happened without actually understanding why they happened or why we still talk about them. Davis does an excellent job to humanize the parties involved, making the stories resonate from their time to our own.