This book is the first to document the response of the Irish Free State to the Spanish Civil War. It is also the story of the military intervention of just under one thousand Irishmen who fought on opposing sides of that war -- a story which has been the source of much curiosity, and controversy. Political extremism in the Irish Free State, of the far left, far right and republicanism motivated this exodus and is an area of increasing popular and historiographical interest. However, these questions have more often been considered in an Irish context rather than as a part of the ideological struggle which gripped Europe in the 1930's.Many aspects of the intervention of the Irish men are questioned in this book, namely O'Duffy's involvement in Spain, his anti-communism and zealous Catholicism. McGarry does not take for granted the presumption that the Irish volunteers simply followed the lead of their charismatic commander in chief. Equally the motives of the Irish in the International Brigades, fighting for democracy and anti-fascism are revealed as far more complex than historical opinion conveys.This is an important study, which identifies many of the critical preoccupations of twentieth-century Irish politics.