As two traditional powers in Europe, France and Germany had played as competitors in the international political arena in the past due to special geo-political factors. They had more than two hundred wars and three great wars in history, either for the Europe’s leadership or for the world’s resources; they had also territorial disputes on Alsace-Lorraine. Therefore, they had been hereditary enemy for hundred years. However, only twenty years later after the Second World War, France and Germany achieved reconciliation and started a new chapter with friendly relationship. How has this what de Gaulle called “miracle of our time” happened and what were the factors that made it happen? The purpose of this thesis is to answer these questions. In this thesis, the development of diplomatic relations between Germany and France in the post-Second World War is the main focus, and the theory of realism serves as a cornerstone for analysis. According to the main features of Franco-German foreign relations, the paper takes the Franco-German relations history into three phases: ‘hereditary enmity’ from 1871 (or before) to 1945; the ‘reconciliation’ of 1945–63; and the ‘special relationship’, from 1963 to present. The first phase explains how hereditary enmity had been formed since 1871. The second phase discusses how France and Germany shifted their attitude: from enmity to amity. The last phase ascertains their relations since the Élysée Treaty. After careful analysis of the gradual progression of Franco-German Page 4 of 109 reconciliation and European integration, this paper draws a conclusion of the reasons for reconciliation. European integration is consistent with France and Germany’s common interests and mutual needs from the very beginning till now. This is why the Franco-German Axis is sustained and works well, and it provides fundamental support for European integration’s irreversibility. Franco-German reconciliation may also offer lessons and enlightment for Sino-Japanese reconciliation and East Asian regional cooperation.