In this chapter we focused on Europe since contemporary international politics, for good and for bad, was shaped by Europeans and by nonEuropeans copying European examples. This is a story of how the state emerged as a sovereign actor in the late Middle Ages by simultaneously rejecting the traditional claims made by universal and local institutions. It is a story of how the state went on to strengthen its power by means of bureaucracies and armies. European states were always competing with each other, and while the military competition had disastrous effects in terms of human suffering, the economic competition that took place was a spur to development and social change. In the course of the nineteenth century, the state was transformed into a nation-state in which, in theory at least, the people as a whole were in charge. There were great hopes that nation-states would be more peaceful in their relations with one another, but these hopes were soon dashed. Nation-states were ferocious colonisers and in the twentieth century the world as a whole suffered through two devastating world wars and came to the brink of nuclear Armageddon during the Cold War. In the twenty-first century there are once again hopes for a better future, but as long as the European state-system (now the international system) lasts a more enduring peace is unlikely.