This article proposes a study into the youth organisations of a region located at the crossroads of Europe, between France and Germany, the Alsace. The analysis centres more specifically on the period between 1918, since most of these organisations were born out of the Great War, and the early 1970s, when they entered into a pattern of decline. In particular, we shall devote our attention to five phases in the development of these organisations, in the course of which the young people of the Alsace experienced a singular form of engagement: between 1918 and 1932 at a time of re-appropriation of the French lifestyle, from 1932 to 1939 in the face of rising regional autonomist pressures, from 1940 to 1945 when the region was under annexation by Germany, from 1945 to 1958 owing to the process of local reconstruction in a thoroughly ‘French’ environment, and finally between 1958 and 1970 as young Alsatians found themselves affected by the deep social and cultural changes taking place. Such a choice of chronology is in many ways original if one considers the European historical works devoted to youth movements. But the singularity of the political and cultural history of this French province fully justifies it. Our research is indeed articulated around three fundamental sets of issues, which apply specifically to the Alsace: inter-confessional relations, the connection between private initiative and public policies, and the dialectical relation between region and nation. This study aims to show that ultimately, between the end of the First World War and the beginning of the 1970s, youth organisations in the Alsace contributed to the affirmation of the young, and later to the forming of numerous trade union leaders, Youth and Sport authorities and high ranking civil servants. This it did in a manner that was always relatively specific. However, such a regional specificity does not lead to the establishment of particularisms, but rather it helps to situate a history in which singular patriotic, religious and political stakes are deeply interwoven.