British soldiers have been known as Tommies for centuries, but the nickname is particularly associated with the British infantryman in the trenches of World War I. In August 1914, a small professional force of British soldiers crossed the Channel to aid the French and Belgians as the German army advanced. As it became apparent that the war would not, in fact, be over by Christmas, a vast drive for volunteer soldiers began. As enthusiasm for enlistment tailed off, eventually conscription was introduced in order to replenish the forces weakened by years of bloodshed. By 1918 the British Army was transformed, fielding 5.5 million men on the Western Front alone. These Tommies fought an entirely new type of war, living in vast trench systems, threatened by death from the air and gas attack as well as by bullet, bomb, or bayonet. This introduction explores the experience of Tommies on the Western Front, explaining how their war evolved and changed from the mobile battles of August 1914 to the final days of the war, and discussing daily life as an infantryman on the front line using first-hand accounts, contemporary poems, and songs.