This chapter explains how international society emerged and was globalised. Its main purpose is to explore how the European sovereign states-system expanded across the globe to become the truly international order of sovereign states that we see today. The first part of the chapter examines how the expansion of the states-system came about and how it has been analysed. The second part provides a critical discussion of how the spread of the states-system has been understood in IR. It aims provoke thinking about the enduring Eurocentrism that continues to bedevil our theorising of international politics.