For almost half a century, population historians have created datasets on life courses from archival sources such as parish records, tax records, censuses and population registers. Their time span ranges from medieval times to the present day. These datasets are essential to understand how economic, social and cultural changes had an impact on the lives of ordinary persons and how these persons, in turn, shaped their surroundings and their destinies by strategies of survival and improvement. Recent developments in ICT facilities and methodologies have increased the scale and the analytic power of these individual level datasets significantly. Thus, in several countries, large regional or even national datasets have been made available for research. New methods of record linkage and new statistical tools are being developed to improve the coverage of these datasets and to deal with the shortcomings of the sources by combining related pieces of information. European administrators have kept more detailed records than anywhere else in the world for centuries, but it is only now that the analytical power inherent in this uniquely rich source material is integrated in ways that bring out the comparative advantage for research on the history of the European population.