In recent years, Joschka Fischer?s Berlin speech has started off the debate on a European Constitution. Subsequently, the establishment of a potential constitution for Europe became an important political issue.First signs of the European idea can already be found in ancient Greece and Rome. From the 14th century onwards, the idea of a unified Europe gained more and more significance and in 1306, Pierre Dubois developed the first plan to create a ?European Confederation?. Until the beginning of the 20th century, all plans for the unification of Europe were merely of theoretical nature. After World War I, the idea of a European Constitution became more important as individuals and European associations focused on a unification of Europe and developed drafts of a European Constitution. In this particular context, the initiatives of two individuals need to be mentioned: the Pan-European Movement established by Richard Coudenhove-Kalergi and the Memorandum drafted by the French Foreign Minister Aristide Briande.In 1941, resistance groups emerged all over Europe as a result of expulsion, violation of human rights, and the wave of Jewish arrests. One of the goals of the resistance groups was the design of the future Europe as a federative entity. After the end of World War II, the idea of a union of European states was still present. The present thesis focuses on the fact that more recent constitution drafts incorporated parts of preceding drafts; furthermore, it tries to explain why the concept of a unified Europe could not be implemented in the interwar period. In addition, this paper discusses the draft of the Convent - which can be traced to the major debates of the last decade ? and tries to demonstrate that the idea of a European Constitution is still a matter of interest.