This volume is a study of the forty years of the Diputación Provincial de Zaragoza (DPZ) in the field of international solidarity and development cooperation. It addresses the origin and characteristics of decentralised development cooperation, as well as the place that the DPZ has occupied in the Aragonese system of international cooperation, including trends in project financing.It also records the role and impact of education for development and global citizenship in Aragonese society. Finally, it brings together the lessons learned, the personal assessments of those involved, and outlines the complex challenges of the future.