The aim of this book is to provide an insight into the landmark rulings of the Court of Justice of the European Union (CJEU) in European Criminal Law (ECL). As in other areas of EU law, the decisions of the CJEU have been a driving force for development and integration. By analysing the impact of these leading cases on EU and national law, the book provides a diachronic and multifaceted picture of the Court’s approach to criminal law.