The study of military history has undergone drastic changes in recent years. The old drums-and-bugles approach will no longer do. Factors such as economics, logistics, intelligence, and technology receive the attention once accorded solely to battles and campaigns and casualty counts. Words like "strategy" and "operations" have acquired meanings that might not have been recognizable a generation ago. Changing attitudes and new research have altered our views of what once seemed to matter most. For example, several of the battles that Edward Shepherd Creasy listed in his famous 1851 book "The Fifteen Decisive Battles of the World" rate hardly a mention here, and the confrontation between Muslims and Christians at Poitiers-Tours in 732, once considered a watershed event, has been downgraded to a raid in force.