This chapter argues that there are two major grey areas in knowledge about competition policy at the scale of the European Union (EU): its doctrinal foundations and its actual application within specific industries. It argues that EU competition policy has indeed become an ever-present aspect of the government of industries in Europe. Since the 1950s, the EU's competition policy has progressively been intensified, densified and stabilized. During this process of institutionalization and reinstitutionalization, a number of enduring and recurrent features have developed in three stages: the first stage revisits the establishment, consolidation then intense reactivation of EU competition policy that occurred between the 1950s and the 1980s; the second stage narrows the focus to the activation of EU competition policy as a key instrument of EU-scale economic government in the 1980s and 1990s; the third stage highlights reforms that took place in 2003-2004 which reinstitutionalized the ideological, normative and process-defining foundations of this trans-industry regulation.