This project aims at investigating, from a historical perspective, the transformation of European diplomacy that resulted from the European integration process from 1945 to present. More specifically, the proposal will focus on the three following interrelated aspects: (i) The transformation of inter-state diplomacy: by removing the threat of war as foreign policy option and by establishing supranational regime, EU integration process challenged the Westphalian system of international relations;(ii) The transformation of the diplomatic agenda: European integration process contributed to expand the diplomatic agenda to new issues such as trade, monetary issues, and others;(iii) The creation of new multilateral framework of negotiations: these multilateral frameworks such as the Council of Ministers led to new diplomatic practices aimed at problem solving.The proposal is aimed at looking at these three main aspects through the teaching of a course, twice a year, using a problem solving learning method. It will be based on the critical analysis of historical documents such as pamphlets, speeches, as well as legal documents, e.g. Treaties, EU legislation and EU main case law. It also includes the organization of trainings sessions offered by the module leader to prepare the students for the EU simulation (see below) In addition, the proposal includes the organization of two public lectures a year by the Ambassador based in Sofia of the country holding the rotating presidency of the Council of the European Union. Finally, the project includes the organization of the yearly EU simulation with financial support for Bulgarian high school students. This proposal is mainly justified by the need to anticipate the fact that Bulgaria will be holding for the first time in the second semester of 2018 the rotating presidency of the Council of the European Union.