1915 was characterized by deadlock and a widening of the conflict. British cities were bombed by zeppelin airships, german u boats attacked neutral ships and gas was used. Documentary series looking at the course of wwi from the assassination of archduke franz ferdinand to the armistice on 11 november 1918. In between, millions perished at ypres, verdun, the somme and globally. It saw the introduction of the tank, the airplane, submarine warfare and the use of poison gas and on the home front the women's army, auxiliary corps and the first air raids. This volume continues the story into 1915, when the great mobile battles of the previous year had resulted in stalemate following the defeat of germany's drive towards paris. Both sides began to dig in, making the first moves towards constructing the vast trench networks that would result in years of attritional warfare.