This chapter examines how the nation-state came into being and how it became dominant as a political unit. It first presents a general and streamlined portrait of the state—a concept that sociologists inspired by Max Weber might call an ideal type. In particular, it considers some of the characteristics of a nation-state, including monopoly of legitimate violence, territoriality, sovereignty, plurality, and relation to the population. The chapter proceeds by discussing a more expansive concept of the nation-state, taking into account the role of law, centralized organization, the distinction between state and society, religion and the market, the public sphere, the burden of conflict, and citizenship and nation. The chapter also describes five paths in state formation and concludes with an assessment of three main phases which different European states have followed in somewhat varying sequences: consolidation of rule, rationalization of rule, and expansion of rule.