The second millennium of mankind has been characterised by almost incessant warfare somewhere on the face of the globe. The Art of War in Twenty Battles serves as a snapshot of the development of warfare over the past 1,000 years, illustrating the bravery and suffering mankind has inflicted upon itself in developing what we call the 'Art of War'. Here military historian Anthony Tucker-Jones selects twenty battles that illustrate the changing face of warfare over the past thousand years – from the Viking shield wall to long bows and knights, the emergence of gunpowder and finally the long-range faceless warfare of today. This is a look at the killing game and its devastating impact.