The years from 1914 to 1918 saw a whole series of complex and very rapid changes in infantry tactics, which fundamentally altered the way wars had been fought for 150 years. This two-part study describes and illustrates the development of infantry equipment and weapons; of support weapons; of field fortifications; and, most importantly, exactly how these items and techniques were all employed in attack and defence. The texts are illustrated with contemporary photos and diagrams, and with new colour plates combining details of uniforms, equipment and weapons with 'bird's-eye views' explaining their use in battle. In short, they offer a detailed but accessible tactical guidebook on 'how to fight a trench war'.