 Complete the following phrase:  The Face of Battle is a 1976 non-fiction book on military history by the English military historian John Keegan. It deals first with the structure of historical writing about battles, the strengths and weaknesses of the battle piece, and then with the structure of warfare in three time periodsmedieval Europe, the Napoleonic Era, and World War Iby analyzing three battles: Agincourt, Waterloo, and 