The purpose of this book is to enter into the history of the mental-social phenomena that are the word sovereignty and the myth of Westphalia. Given the circularity of language, the project proposes to examine the reality-creating role of language, as an organic instrument of social power within humanity. In semiotic terms, the complex structures of words and also myths form part of sign-systems in which they can both represent and create reality. These are the passive and active functions of language, which explain that words and myths not only represent and describe reality but may also play a leading part in creating and transforming reality, thus demonstrating and being used to carry fabulous power within humanity.The Peace of Westphalia is analysed to show that, in spite of what actually took place in 1648, Westphalia has had an incredible social effect in international law, standing for the proposition that it signalled the beginning of a new era based on state sovereignty. However, it is argued that Westphalia constitutes a myth, an aetiological myth, which has provided a way for society to explain itself to itself, that is, a way for international society to explain its genesis to itself. As regards sovereignty, it is shown that Jean Bodin introduced the word in Six Livres for the purpose of having the French ruler enjoy supreme power in the hierarchical organisation structure of society. This is the original creative and transforming social effect on the shared consciousness of humanity for which the linguistic sign must be credited, which has continued, unaltered, to this day. With respect to Droit des Gens, it is demonstrated that Emer de Vattel utilised and actually changed the reality associated with sovereignty also for a specific reason, namely, to carry out its externalisation - the ruling entity was now to enjoy exclusive power to govern, which entailed being the sole representative of the people both internally and externally, and also meant that it could not be submitted to any foreign state or to any higher law externally. Vattel's use of the word has had an extraordinary effect on the shared consciousness of society, including that of the emerging international society, which is still very much present today. These two archetype cases in which 'sovereignty' developed show how this word has really had two paradigms over the years, that is, it has represented and created the two distinct realities of the internal and the international.