The purpose of this research was to move away from the analysis of national governments and their role in EU environmental policy-making and highlight instead subnational regions and their influence on the success, or failure, of EU environmental policies. In particular, the research has argued that the study of subnational regions and their actors can help explain why the EU is suffering from an implementation deficit in the environmental policy area. By distinguishing between national and subnational government levels the aim was to contribute new and vital insights to the study of EU environmental policy implementation, insights which have been hitherto neglected by ‘state-centrist’ analyses.