Established in 1858, the Irish Republican Brotherhood was a secret, oath-bound movement dedicated to bringing about revolution in Ireland. This book is a result of a major conference to mark the 150th anniversary of the founding of the Irish Republican Brotherhood and includes essays on Fenianism in its diasporic, transnational and imperial context; political violence; republican ideology and popular politicisation; culture, religion and identity; and memory and commemoration. This is the first publication to consider Fenianism as the truly international phenomenon it represented and includes essays from international scholars assessing the impact of Fenianism - a movement founded in America by the Irish immigrant community - throughout Ireland, Britain, continental Europe, the Americas and Australasia. The book spans the full chronological range of Fenian movement, from its origins in the aftermath of the Young Ireland movement, through its existence as a mass revolutionary movement in the 1860's, the long period as an underground revolutionary conspiracy, culminating in its role as the driving force of the Irish revolution between 1916 and 1921.