Religion and nationalism are two of the most powerful forces in the world. And as powerful as they are separately, humans throughout history have fused religious beliefs and nationalist politics to develop religious nationalism, which uses  religious identity to define membership in the national  community. But why and how have modern nationalists built religious identity as the foundational signifier of national identity in what sociologists have predicted would be a more secular world? This book takes two cases - nationalism in both Ireland and Turkey in the 20th century - as a foundation to advance a new theory of religious nationalism. By comparing cases, Goalwin emphasizes how modern political actors deploy religious identity as a boundary that differentiates national groups This theory argues that religious nationalism is not  a knee-jerk reaction to secular modernization, but a powerful movement developed as a tool that forges new and independent national identities. "In an age where religious nationalisms and populisms are on the rise, Goalwin's comparative-historical work is a welcome contribution for comprehending how religious identities and politics interact. A valuable source for social scientists as well as non-specialists who are interested in this complex phenomenon." -- Efe Peker ― co-author of Challenging Neoliberalism at Turkey’s Gezi Park: From Private Discontent to Collective GREGORY J. GOALWIN is an assistant professor of sociology at Aurora University in Illinois. His research has been published in journals including S ocial Science History , Patterns of Prejudice , Studies in Ethnicity and Nationalism , Nationalities Papers , and the J ournal of Historical Sociology .