This dissertation is based upon a study of the active service magazines produced by British and Dominion troops serving in the various active war theatres of the First World War. These magazines have never previously been systematically examined, and the dissertation first analyses them as a phenomenon in their own right, then uses them in conjunction with other sources to construct an analysis of morale in the British and Dominion forces and the means by which it was sustained. The analysis of morale and the influences upon it forms the main body of the text. It deals particularly with the infantry, because of the hardness of their lot and their dominant role in mutinies in other armies. It analyses their organisation and conditions of life, but it focuses most attention on the time spent behind the lines in rest and reserve, and particularly on the recreations enjoyed by the troops. It attempts to show that these aspects of the infantrymen's service have been unduly neglected, were important, and had an influence over attitudes throughout the period of service and perhaps even beyond it. Arising from this study, the dissertation seeks to demonstrate a considerable degree of continuity in attitudes, as expressed through the popular cultural media of the troops, from civilian to military life. It considers the importance of this for understanding the behaviour of the men as soldiers and, to a lesser extent, as veterans after the war. It also looks at similarities and differences of background and approach between the various national contingents which made up the British and Dominion forces, and looks briefly at perceived contrasts with other armies. In conclusion, it looks ahead to the use of troop recreations in the Second World War, and attempts to assess their importance in the First, both for morale and for the historiographical debate about continuity and change in the soldiers' experience.