War: A History in 100 Battles by Richard Overy
7 out of 10

With minor exception, people everywhere have been continuously fighting each other en masse for thousands of years.  A valiant leader may claim the day.  Sometimes the underdogs win.  New technology can tilt the field.  A clever deceit might lead to victory.  Courage is often contagious.  Though, even the non-superstitious admit that the timely arrival of reinforcements, abrupt condition shifts and unexpected performance can define an outcome.