The aim of this thesis is to explore the war writings of Patrick MacGill, James Hanley and Liam O'Flaherty, working class, Roman Catholic Irishmen, all of whom fought in the trenches as privates and who, collectively, it is argued here, constitute a distinct trio of war writers. Through considerations of class, camaraderie, violence, religion, trauma and the body, and engaging with scholars such as John Fordham, David Taylor and Sarah Cole, this thesis will consider these Irish soldiers within a cultural, social and historical context. Central to this examination is the idea that the motives for enlistment and the experience of army labour and even combat was such that military service was perceived as work rather than a duty or vocation undertaken in support of any prevailing doctrines of patriotism or sacrifice. For these Irishmen their enlistment was a form of emigration for work and their resulting exploration of national and personal identity encompasses ideas of home as exile, building upon the work of Clair Wills, and a sense of continuity for such working class individuals between peacetime and wartime roles. The men's Catholicism also shaped their aesthetic and philosophical responses to the war, even while the war conversely troubled their faith or confirmed their religious skepticism. With these ideas in mind, the war writing of these men will be located within both an Irish and a pan-European literary working class tradition, thereby permitting the texts to be viewed within a wider context than literature of the First World War, and from a perspective that goes beyond Ireland and Britain. These characteristics shape a perspective on the conflict very different from that of the canonical officer-writers, men such as Siegfried Sassoon, Robert Graves or Edmund Blunden, whose work will be considered alongside those of the three Irish soldier-writers.