Set against the historical background of Spain's unification as a modern state, this book is a study of a complex, frequently violent, political phenomenon - Basque nationalism - which after ninety years continues to constitute a major challenge to Spain's established political order. It examines the origins of Basque nationalism in the Basque industrial heartland of Bilbao in the 1890s and analyses its development up to 1980 when the Basque country finally achieved home rule. In particular, the book shows how Basque nationalism operated upon the residents of the Basque country, divided by culture, loyalties, divergent economic and political aspirations and history, to create a new and exclusive political entity - the Basque nation. The main fieldwork was conducted during the two years surrounding the death of General Franco in 1975, a period of exceptional violence in the Basque country that marked Spain's transition from an authoritarian regime to a democratic one. Using a theoretical approach, the book provides an empirical analysis of one of Spain's most intractable political problems during a decisive period of Spanish history.