Konzept einer intermediären Datenstruktur (IDS) zur Integration national unterschiedlicher Datenbanken«. In recent years, studies of historical populations have shifted from tracing large-scale processes to analyzing longi-tudinal micro data in the form of 'life histories'. This approach expands the scope of social history by integrating data on a range of life course events. The complexity of life-course analysis, however, has limited most researchers to working with one specific database. We discuss methodological problems raised by longitudinal historical data and the challenge of converting life histo-ries into rectangular datasets compatible with statistical analysis systems. The logical next step is comparing life courses across local and national databases, and we propose a strategy for sharing historical longitudinal data based on an intermediate data structure (IDS) that can be adopted by all databases. We de-scribe the benefits of the IDS approach and activities that will advance the goals of simplifying and promoting research with longitudinal historical data.