The research aims to uncover an often disregarded dimension of the concept, the identity politics of sovereignty, and to integrate it within a dualistic framework of the concept. Based on the assumption that sovereignty is an historically contingent concept and thus does not have a fixed definition, it will be argued that sovereignty should be understood as demarcating factor organising political reality in separate spheres: the inside versus outside of states (i.e. the domestic versus the international sphere), and the self versus the other on the international plane (i.e. identity politics of sovereignty). The second dimension of sovereignty is centred around the belief that the unifying character of a common European identity was crucial to the development of conceptions of sovereignty during the 19th century. The use of a standard of civilisation indicates how European imperial powers divided the world between the civilised European self and the barbaric Non-European other. By analysing dynamics that emerged in the 19th century and continued in the 20th century, the proposed research aims to examine the contemporary understanding of sovereignty. It will apply its dualistic framework of sovereignty to the analysis of the apparent reassertion of sovereignty. For instance, the recent vote of the UK to leave the European Union appears to indicate the culmination of a narrower understanding of the identity of self and correspondingly a stricter understanding of sovereignty.