Social and spatial inequalities between and within core and peripheral regions have re-emerged as a major economic and political issue in developed economies. Such divisions have generated economic and social discontent and growing levels of political support for populist and nationalist parties in peripheral regions, particularly certain old industrial areas. This turmoil fuelled the Brexit vote in the UK and the election of Donald Trump in the US as well as support for the Rassemblement National (National Rally) and Gilets Jaunes (Yellow Vests) in France and the Alternative für Deutschland in Germany. In response, researchers, commentators and politicians have voiced concerns about the places 'left behind' by globalisation, technological and economic change. While welcome in increasing the political visibility of social and spatial inequalities, the 'left behind' category risks hiding and over-simplifying the different experiences and development paths of people and places. The aim of the project is to develop a new understanding of demographic and socio-economic change in peripheral regions, examining the circumstances and prospects of places and people currently categorised together as 'left behind'. It will advance understandings of peripheralisation as an on-going process driven by the geographical concentration of people and prosperity in large urban centres alongside the decline or stagnation of other regions. The research is concerned with inner peripheries defined by their disconnection from external territories and networks, particularly urban regions and intermediate areas close to cities experiencing demographic and socio-economic stagnation or decline. Taking an approach that compares the experiences of France, Germany and the UK in their western European context, the research has four objectives: i) To understand the distinctive circumstances and development pathways of peripheral regions, overcoming the tendency to subsume different kinds of places beneath the broad category of 'left behind'; ii) To assess the relationships between the population dynamics of peripheral regions and socio-economic, health and political outcomes, covering both people moving from, and staying within, peripheral regions to redress the existing research bias towards migration between regions; iii) To examine the livelihood activities and practices of residents in peripheral regions, remedying the neglect of how 'ordinary' people deal with peripherality; iv) To identify new policy responses that combine conventional and alternative perspectives, moving beyond the reliance upon growing larger cities and spreading their prosperity to surrounding regions. Using a range of research methods and a cross-national research design, the research team will address these objectives by undertaking the following tasks: i) Identifying and categorising peripheral regions across western Europe to identify their different pathways of development and the key dimensions and processes of concentration and peripheralisation, drawing upon international and national secondary quantitative data; ii) Investigating the different experiences and outcomes for people moving from, and staying in, peripheral regions in France, Germany and the UK using secondary quantitative data; iii) Examining people's everyday livelihood strategies and practices in peripheral regions through six neighbourhood case studies (two per country) based on semi-structured interviews, non-participant observation, livelihood infrastructures mapping, and focus groups; iv) Assessing current and informing future policy approaches to address the varied situations of peripheral regions through analysing secondary documentation and key actor interviews. v) Synthesising findings, relating them to the overall project aim and objectives, and writing up the project's research outputs (8 international journal articles, 1 monograph and policy report).