The regular armies which marched off to war in 1914 were composed of massed riflemen, screened by cavalry and supported by artillery; their leaders expected a quick and decisive outcome, achieved by sweeping manoeuvre, bold leadership and skill at arms. Eighteen months later the whole nature of field armies and their tactics had changed utterly. In sophisticated trench systems forming a battlefield a few miles wide and 400 miles long, conscript armies sheltered from massive long-range bombardment, wielding new weapons according to new tactical doctrines. This first of two richly illustrated studies explains in detail the specifics of that extraordinary transformation, complete with ten full colour plates of uniforms and equipment.