The idea of civilization permeates public discourse – as in the case of the construction of the ‘war on terror’ in the United States in the aftermath of 9/11. It frequently appears in media discussions of ‘savagery’ such as the beheadings of hostages by ‘Islamic state’. It has long been part of everyday discussions of the ‘barbarism’ of the death penalty. It is curious that a concept which first appeared in elite circles in France in the final part of the eighteenth century has become so fundamental to social attitudes to violence. Sophisticated explanations of how this process occurred exist but they require further development. It is important to understand how European state formation, empire and international society evolved as part of one overall process of civilization. The idea of civilization has fallen into disrepute in many circles in recent times because of its association with images of Western superiority and progress that brought misery to many. In a break with Eurocentrism, academics have referred to civilizations in the plural rather than in the singular. The idea of a process of civilization can be constructed along similar lines – to describe, in an explicitly non-evaluative way, social and political transformations that have taken place found in different societies across human history. This lecture argues that the idea of the civilizing process provides students of international relations with an important resource for explaining long-term developments in relations within and between human societies.