For nearly twenty years, EU antitrust enforcement has been governed by Regulation 1/2003, which ushered in a sweeping reform of the procedures for the application of Articles 101 and 102 TFEU. This systematic article-by-article expert commentary on the Regulation, with additional perspectives and critical views by particularly experienced and qualified authors, provides an in-depth examination of the Regulation’s legal achievements, implications, and promise for the future. Analysis of each of the Regulation’s articles covers such aspects as: legislative history; rationale and context; practice of the Commission and, where relevant, of the national competition authorities; case law of the Court of Justice of the European Union; international aspects; and outstanding and problematic issues. Along with many of the article commentaries, ‘boxes’ have been added on specific issues of particular salience. The critical reflections of the book’s second part include perspectives from members and staff of the Court of Justice of the European Union and of the European Commission’s Directorate General for Competition and Legal Service, heads of national competition authorities and of national courts, counsel, economists, consumer organisations, and academics. There are also comparisons with various aspects of antitrust enforcement in France, Germany, the Netherlands, and the United States. With this unparalleled book, practitioners and in-house counsel, as well as case-handlers and policymakers, will approach any competition case before the Commission with full awareness of the applicable procedural rules. They will gain a clear understanding of the enforcer’s powers and duties, as well as of the various options available to the undertakings involved in antitrust proceedings and their rights.