Many scholars who have studied nations and nationalism have observed that nationalist movements draw upon mythologised narratives of figures from their nations' pasts to build a sense of national identity and to articulate their vision. Drawing upon the ethno-symbolic approach to nations and nationalism, this thesis seeks to identify the major hero myths, as one form of mythologised narrative, drawn upon by the Provisional IRA during the period of conflict in Northern Ireland between 1969 and 1998. In so doing it examines the origins and development of those myths across the history of Ireland, and of the republican strand of Irish nationalism since the turn of the twentieth century. It identifies the pivotal role of the early twentieth century republican, Patrick Pearse, as republicanism's political archaeologist par excellence, and examines the enduring influence of three factors on the form that such myths took: Celtic culture, Roman Catholicism, and socialism. The thesis further situates the narrative chain of the hero myths within the broader context of the Provisional IRA's wider mythological system, and interrogates the purposes that these myths fulfilled for the movement. In so doing, it reveals that not only did the hero myths, as symbolic resources of the Irish nation, fulfil purposes related to the nation itself, but that the strategy employed in pursuit of the national objectives, insurgency, also imposed its own requirements on those purposes. This has profound implications for orthodox understandings of the role of “blood sacrifice” within the ideology and world-view of the Provisional Republican Movement, as this thesis argues that the role of that concept has been misinterpreted to this point. On the theoretical level, this thesis amends and refines the conception of myth within the ethno-symbolic approach to nations and nationalism, bringing it into line with the work of scholars who have studied the theory of myth. Furthermore, it has considered how the means of pursuing the national objective helped to shape the concept of the nation and ideas of national identity.