This introduction presents an overview of key concepts discussed in the subsequent chapters of this book. The book examines the centrality of biological invasions in the contemporary scientific, academic and regulatory panorama by applying the Driving forces-Pressure-State-Impact-Response (DPSIR) model. It introduces a specific analysis of the action of the Union in the field of the protection of biodiversity in general, and of biological invasions in particular. The book describes the European Union as the only contemporary example of a regional organisation pursuing factual and comprehensive integration. It illustrates the contents of the proposal made by the Commission and the legislative iter followed by the sui generis Union's bicameral system – formed by the European Parliament and by the Council – towards the adoption of regulation 1143/2014. The book evaluates the strengths and weaknesses of the act, together with threats and opportunities deriving from such a regulatory intervention by the European Union.