For the last twenty years, the rhetoric of civilization has clawed its way back into international discourse, and into books and articles written by political scientists and scholars of international relations. Most of these emphasize the close connection between the concept of civilization and colonialism, suggesting that the main purpose of civilizational language in international relations has always been an imperial one. In this thesis, I argue that such interpretations are mistaken, and use British and German debates to retrace the complex political development of a concept at once popular and indeterminate, which Bismarck referred to as being covered by a 'glittery fog'. I argue that political civilizational language first started to be advanced by European liberals, who were not advocating colonialism, but instead opposing dynastic and non-national politics within Europe. Following these debates, the rhetoric of civilization was first officially employed in the Crimean War, and from then on remained an important fixture primarily of inner-European politics. The wars of the 1860s that followed in its wake were, I argue, as much wars about the correct definition of civilization, as they were about nationalism. It was only in the 1870s that the concept of civilization started to acquire the global profile and sometimes imperial connotation so often associated with it and the nineteenth century in general. But the bloom of this civilizational language was a short one. From the 1880s onwards, the appeal of civilization started to decline as the critique of modernity and its negative effects, first voiced by socialists and radicals, started to reach mainstream liberalism. With the end of the nineteenth century, I argue, the classic language of civilization also came to an end. Larger sections of the European public started to question the ulterior motives behind civilizational language and the main conflicts of the turn of the century, the Boer war and the Boxer rebellion, also produced new discourses of civilizational plurality, through which appeals to the singular of civilization became ever more difficult.