Abstract: As a key concept for understanding the modern state, sovereignty was subjected to permanent re-evaluation, shading, reformulation or reinterpretation, following the evolution of the representations on the state. Its utilization in legitimizing or justifying different or even opposed political conceptions is evidence of both its endurance and actual relevance. The peculiar legal nature of the European Union requires the examination of the sovereignty concept from a different perspective. The gradual transfer of sovereign powers of EU member states to the Union demands a re-evaluation of scope and functions of sovereignty in public law and in the "Staatslehre". This paper upholds the thesis that the most important mutation in the field of sovereignty theory concerns the issue of determining its bearer, while sovereignty as such still remains unavoidable in legitimizing political decisions of national and supranational entities.

Keywords: sovereignty, European Union, statehood, nation-state, international law, municipal law, legal positivism