In this scholarly and compelling book Dr Colm Campbell offers a detailed legal analysis of emergency powers and assesses their impact upon the outcome of political conflicts. Drawing upon extensive archival materials, the author examines the effect of emergency law on the battle for legitimacy in three jurisdictions: Ireland under British rule 1918-21; the Irish Free State 1922-25; and Northern Ireland, 1921-25. Carefully researched and cogently argued, this book will appeal not only to historians but also to constitutional lawyers, political scientists, and scholars interested in civil liberties and the history of laws relating to political violence.