This chapter describes the historical development of competition rules in the context of European integration. It provides an overview of the academic literature on European Union (EU) competition policy. The bulk of the literature on EC/EU competition rules stems from legal scholars and economists. Legal scholars generally address questions of interpretation of existing competition rules and case-law, legal consistency, and procedural equity, as well as predictability and transparency – concerns generally also shared by the wider business community. The 1951 Treaty establishing European Coal and Steel Community included detailed supranational competition provisions and in the subsequent Rome Treaty in 1957, which established the European Economic Community, competition received a strong constitutional basis. Competition rules are at the heart of the integration process, most notably by reconfiguring national markets into European single market. The European Commission's Directorate General for Competition is the supranational competition authority in charge of enforcing the rules.