Dictionary of Wars, highly praised in its first edition (1986), has now been published in a completely revised, updated, and expanded 2nd Edition.
The Dictionary provides summaries of all notable wars from earliest recorded history to the present day. It affords the general reader and student with quick, useful, and accurate information - the who, where, when, what, why and how on the more than 1,800 recorded wars in human history from 2000 BC to the present. Completely updated, the Second Edition includes an additional 70 entries - on such major events as the Gulf War, the invasions of Panama and Haiti, and the Bosnian crisis.
This is a "must" when reading history. Using this book, one can read about the wars prior, perhaps even leading up to the "studied" war and conversely, one can read about the ramification of decisions made during the "studied" war.
This reference book provides a very basic explanation on a very wide range of wars over several thousand years. You shouldn't expect detailed descriptions of the wars here, but it will give you basic information on most wars of the past, which will be a good starting point if you then wish to go on and read about them in more detail.