European societies face rapid social changes, challenges and benefits, which can be studied with traditional tools of analysis, but with serious limitations. This rapid transformation covers changes in family forms, fertility, the decline of mortality and increase of longevity, and periods of economic and social instability. Owing to population ageing across Europe, countries are now the experiencing the impact of these rapid changes on the sustainability of their welfare systems. At the same time, the use of the space and residential mobility has become a key topic, with migrations within the EU countries and from outside Europe being at the center of the political agenda. Over the past decade research teams across Europe have been involved in the development and construction of longitudinal population registers and large research databases, while opening up avenues for new linkages between different data sources (ie administrative and health data) making possible to gain an understanding of these fast societal transformations. However, in order to work with these types of datasets requires advanced skills in both data management and statistical techniques. LONGPOP aims to create network to utilize these different research teams to share experiences, construct joint research, create a training track for specialist in the field and increase the number of users of these large – possibly underused - databases, making more scientists and stakeholders aware of the richness in the databases.