This consortium proposal addresses the diverging fortunes of the rich, the poor and those in between. Our aim is to advance our understanding of how socioeconomic inequalities are changing, what is driving such trends and what, if anything, can be done. An undertaking of such ambition and complexity warrants an approach that combines state-of-the-art research from several disciplines. To that end, the current Methusalem grantee, the Centre for Social Policy Herman Deleeck, is joining forces with the Centre for Urban History and the Institute for Development Studies in the Antwerp Interdisciplinary Platform for Research into Inequality (AIPRIL) to continue and expand its work on the topic of socioeconomic inequality, enlarging the temporal and geographical scope this topic requires. We propose a seven year research program that seeks to make methodological, theoretical, and empirical advances in this rapidly evolving research field, building on insights from economics, sociology, economic history and development studies. The research program contains four strategically selected research streams: 1) New data and tools for the measurement of inequality; 2) Curbing inequality; 3) Urbanisation and Inequality; and 4) Shocks and Inequality.