Sandrina Antunes is Assistant Professor in the Department of Political Science at the Universidade do Minho, Portugal, and a Scientific Fellow at the Université Libre de Bruxelles, Belgium. She is an integrated researcher at the Research Centre in Political Science (CICP). Her research interests include regionalism, nationalism, and sub-state mobilization in the EU, with a particular focus on the evolving dynamics of paradiplomacy, Europeanization, and lobbying activities within EU governance structures. Noé Cornago is Associate Professor of International Relations at the University of the Basque Country (UPV/EHU), Spain, and CPD Research Fellow at the University of Southern California Center on Public Diplomacy (2023–25), USA. His research is focused on the contemporary transformations of diplomacy and more specifically in the evolving co-production of domestic and global political order. Carolyn Rowe is Reader in Politics and Co-Directs the Aston Centre for Europe, Aston University, UK. Carolyn has expertise in the analysis of territorial politics in the EU, German federalism and devolution in the UK. She has provided analysis on the role of Brexit, devolved governance and the role of the German Länder in the EU to a number of external organizations, including several EU institutions, the Scottish Parliament, the UK Shadow Europe team, CIPFA and a large manufacturing association. Rachel Minto is Senior Lecturer in Politics at the Department of Politics and International Relations at Cardiff University, UK, where she is also a member of the Wales Governance Centre. She specializes in EU governance, gender equality, and territorial politics. Her current research examines post-Brexit EU–UK territorial relationships and their implications for UK governance. In particular, she explores multi-level governance, Europeanization, and de-Europeanization across the different territories of the UK.