This is a research proposal about changes in the distribution of GDP and population in Europe at the regional level since 1870. The need identified need is that of improving our understanding of the processes of European Integration (EI) associated with regional cohesion and divergence. This subject has often been studied with reference to EU countries, but generally between the 1970s and the present day, or over even shorter periods. To better analyse the long term process of EI, it is necessary to adopt an innovative approach: to adopt a broader geographical and historical perspective based on new data and research questions. Our goal is to analyse regional cohesion in whole of Central and Western Europe over the last 140 years. This will make an academic contribution to one of the most relevant debates in the EU which concerns tensions between countries at the core and occupying peripheral locations in the EU and, more specifically, within the Eurozone.To do this, we will use two indicators from our own datasets. The first, total population at the regional level, will give us a broad overview of the population geography of Europe at the most detailed scale available (Nuts 3) for the period 1870-2010. For GDP, we shall also provide new data for 1900-2010 at the Nuts 2 level. The two datasets cover different areas (Figure 1) and how they complement each other will be one of the subjects discussed in the Methodology section. The two datasets are the result of two different lines of research that we will combine in order to obtain relevant results and develop new lines of work in EI analysis. The corresponding researchers will meet to discuss these issues within this Jean Monnet (JM) project and will carry out academic research together and disseminate the findings. The first work will be to chart and measure the uneven development of European territories since 1870. In a second phase, we will then study the regional cohesion process in a broad context.