The joint project 'Linking Borderlands: Dynamics of Border Regional Peripheries' aims to focus regional studies on European border regions as contact zones and transition areas at the borders of nation states. In this way, ongoing development paths and upheavals in so-called borderlands can be illuminated. The joint approach of the consortium of Saarland University (UdS, lead partner), the Technical University of Kaiserslautern (RPTU), the European University Viadrina Frankfurt (Oder) (EUV) and the Brandenburg University of Technology Cottbus-Senftenberg is based on border studies, which have increasingly developed in a constructivist direction since the 1990s and enable an interdisciplinary approach to border region issues. Together, the Greater SaarLorLux+ and Brandenburg/Lebus border regions are approached in order to put transregional peripheries in relation to each other, which exhibit a varying degree of interdependence in connection with a temporal divergence of EU integration.Five focal points around policy transfer and learning, social practice and language in the context of vocational training, cultural negotiation processes in film, planning cultures and energy transitions are being addressed in order to be able to advise decision-makers in politics and society on current issues and opportunities for cross-border cooperation. Together with the Chair of Regional Development and Spatial Planning at the RPTU, the Department of International Planning Systems is working on the focus area "Planning Boderlands" - planning cultures and structural change processes - in the consortium. Cross-border cooperation in spatial planning and development is confronted with challenges such as different administrative systems, language barriers and infrastructures. However, change processes such as economic and demographic change or digitalization do not stop at national borders and require coordination processes that require joint approaches for specific planning tasks. At the same time, different planning cultures are assumed from a planning perspective, whereby the role of different legal regulations and planning levels must be taken into account. On this basis, the study examines which planning strategies and instruments are used in the two border region peripheries and the extent to which they diverge or conflict. In terms of spatial development, services of general interest and the guarantee of access to infrastructure and services are taken up as European objectives and compared.