War has seemingly always been a part of human history. In many cultures, the invention of writing, and the keeping of those written records that are the basis of most historical research today, is heralded by accounts of the wars of kings and heroic tales of mighty warriors. But the early history of warfare is actually shrouded in mystery. For millennia before the invention of writing, there were humans living as hunter-gatherers around the globe. Did they engage in warfare? Even after warfare became a known part of the human repertoire of activities, the scarcity and haphazard availability of source material means that we can know the course of particular wars or the forms of military organization that lay behind the campaigns in only fragmentary and uncertain ways.
Of course, problems of source material—the incompleteness of the record of evidence, the often biased or problematic nature of the sources we do have, and the different perspectives from which the surviving evidence can be interpreted—are common to all historical investigations. Throughout this book, we highlight some of the instances of these problems in sections set off from the main text.
In this chapter, we move from a brief examination of what can be known about the origins of warfare; to a survey of the major themes of ancient warfare, themes that will recur and form the framework of analysis of the rest of this book; and, finally, to a closer look at the ancient wars and military organizations about which we know enough to say something substantial.