This chapter introduces the idea of a competition–democracy nexus as the object of inquiry of the book and traces its intellectual trajectory across six centuries of legal, economic, and political thought. It shows how early manifestations of the idea of a competition–democracy nexus (competition–democracy nexus 1.0) took shape in the late 16th and early 17th century with the critique of monopoly by Thomas More, the early common lawyers and the English Leveller movement. It also recounts how early liberal thinkers, most notably Adam Smith, James Steuart and Montesquieu, celebrated the advent of competitive markets as a driving-force behind the transformation of the feudal order into a republican society. The chapter also analyses how the idea of a competition–democracy nexus (competition–democracy nexus 2.0) lay at the origin of US antitrust law and had an important bearing on various antitrust paradigms until the 1970s. The chapter further describes the emergence of the idea of a competition–democracy nexus as the central tenet of the German Ordoliberal School before and during the Second World War and its influence on the early days of EU competition law (competition–democracy nexus 3.0).