This book analyses Fenian influences on Irish nationalism between the Phoenix Park murders of 1882 and the Easter Rising of 1916. It challenges the convention that Irish separatist politics before the First World War were marginal and irrelevant, showing instead that clear boundaries between home rule and separatist nationalism did not exist. Kelly examines how leading home rule MPs argued that Parnellism was Fenianism by other means, and how Fenian politics were influenced by Irish cultural nationalism, which reinforced separatist orthodoxies, serving to clarify the ideological distance between Fenians and home rulers. It discusses how early Sinn Fein gave voice to these new orthodoxies, and concludes by examining the ideological complexities of the Irish Volunteers, and exploring Irish politics between 1914 and 1916.