Modern human beings are socialized to take the existence of ethnic and national identities as given and largely unproblematic. Very few individuals would question the apparent normality of this division into nations and ethnic groups however, the intensity of this widespread feeling hides the degree of its historical novelty. This book explores the ideological and institutional underpinnings, as well as the political implications of this powerful modern belief system. This is achieved through subtle theoretical and thorough empirical analysis, both of which draw critically on the leading approaches in the field.