Drawing upon the conceptual framework of legal institutionalism, this book describes the European Union legal system as an autonomous and composite institutional construct grounded on effectiveness (ubi societas, ibi ius and vice versa) and integrated into national legal systems. It focuses on the processes through which the EU legal order is created, monitored, and administered on a day-to-day basis by public institutions, including legislatures, courts, authorities, and agencies, with their origins both in the European Union and member states. Of critical importance is the link between Union law and the normative values that unite European society. Ample references to jurisprudence are provided, key to understanding how the law is applied and how the dynamics among the EU institutions unfold and evolve. This exploration of the basic and structural elements of the European integration process reflects the author's studies, his university teaching, and his experience as the legal counsel of the Italian Government in Brussels. The volume is addressed to students and the academic community, but also to professionals and practitioners.