The 1998 Belfast Agreement in Northern Ireland was thought by many to have at last ended decades of violence that had claimed thousands of lives. But what about those who refused to accept the new dispensation? That the threat might not so easily have been eradicated was given brutal testimony by the Omagh Bombing of August 1998, the worst single atrocity to afflict Northern Ireland in thirty years. Post-Omagh, there were new suggestions that the shock of that crime might itself sound the death knell for republican-inspired violence. The murder of two soldiers and a policeman in Northern Ireland in March 2009 served a stark reminder that such hopes had proved illusory. The irreconcilables have not, it has become clear, gone away . For this reason, it is worth asking, who they are: who are the individuals and groups that now inhabit the Irish Republican milieu? What do they believe? What do they want? And how do they seek to achieve their goals? Legion of the Rearguard offers the first academic analysis of dissident Irish republicanism and its evolution down to the present day. Drawing on first-hand interviews with leading protagonists and detailed analysis of a range of documents and other sources, the author examines the phenomenon in all its forms and explores the when, where, whom, what and why of dissident republicanism.