This chapter discusses what is often regarded as the central institution, not only of domestic or national political order but also of current international or global order—the state. Alongside the state, we must also consider the idea of the nation and the ideology of nationalism—perhaps the most powerful political ideology to emerge in the modern world. There is, however, another form of international political order that has actually been far more common throughout history, and that is empire. With the rise of modernity from around the beginning of the seventeenth century, we also encounter the rise of the modern state and state system in Europe along with ideas about sovereignty, citizenship, the nation-state, and democracy. The chapter then looks at the effective globalization of the European state system through modern imperialism and colonialism and the extent to which these have been productive of contemporary global order.