French–German hereditary enmity (Deutsch–französische Erbfeindschaft, Esprit de revanche) describes the three centuries of hostile relations and revanchism between France and Germany, from the Thirty Years' War to World War II, after which it has been overcome. After 1945, French-German relations became the key to European integration.
France and Germany both trace their history back to being united in Charlemagne's Carolingian Empire before the Treaty of Verdun of 843 divided it into three kingdoms, with the Western and Eastern parts developing into the modern nations, while the central part of Lothair I gave name to Lorraine, an area to be disputed for 1100 years to come. Ambitions to the senior imperial status and the implicit role of leadership over Western Europe that it held were a continual source of friction between France and the states of Germany throughout the medieval and early renaissance periods.
Since the French Revolutionary Wars and the Napoleonic Wars, the leaders of monarchic states not fought only against another, among fellow monarchs, but against a people, which carried the conflict to new levels. The French Levée en masse conscription made armies grow to hundreds of thousands.
Napoleon put an end to the millennium-old Holy Roman Empire in 1806, forming his own Confederation of the Rhine, and reshaped the political map of the German states, which were still divided. The wars, often fought in Germany and with Germans on both sides as in the Battle of the Nations at Leipzig, also marked the beginning of what was explicitly called French–German hereditary enmity. Napoleon directly incorporated German-speaking areas such as the Rhineland and Hamburg into his First French Empire and treated the monarchs of the remaining German states as vassals. Modern German nationalism was born in opposition to French domination under Napoleon. In the recasting of the map of Europe after Napoleon's defeat, the German-speaking territories in the Rhineland adjoining France were put under the rule of Prussia.
The eventual unification of Germany was triggered by the Franco-Prussian War in 1870 and subsequent French defeat. Finally, in the Treaty of Frankfurt, reached after a lengthy siege of Paris, France was forced to cede the Alsace-Lorraine territory (consisting of most of Alsace and a quarter of Lorraine), and pay an indemnity of five billion francs to the newly declared German Empire. Thereafter, the German Empire was widely viewed as having replaced France as the leading land power in Europe.
However, the UK and the US didn't favor these policies, seen as too pro-French so Germany soon recovered its old strength (most of the war reparations were cancelled under the pressure of the UK and the US), then from 1933 under Adolf Hitler, began to pursue an aggressive policy in Europe. Meanwhile France in the 1930s was tired, politically divided, and above all dreaded another war, which the French feared would again be fought on their soil for the third time, and again destroy a large percentage of their young men. France's stagnant population meant that it would find it difficult to withhold the sheer force of numbers of a German invasion; it was estimated Germany could put two men of fighting age in the field for every French soldier. Thus in the 1930s the French, with their British allies, pursued a policy of appeasement of Germany, failing to respond to the remilitarization of the Rhineland, although this put the German army on a larger stretch of the French border.
Finally, however, Hitler pushed France and Britain too far, and they jointly declared war when Germany invaded Poland in September 1939. But France remained exhausted and in no mood for a rerun of 1914–18. There was little enthusiasm and much dread in France at the prospect of actual warfare after the “phony war”. When the Germans launched their blitzkrieg invasion of France in 1940, the French Army crumbled within weeks, and with Britain retreating, an atmosphere of humiliation and defeat swept France.
A new government under Marshal Philippe Pétain surrendered, and German forces occupied most of the country. A minority of the French forces escaped abroad and continued the fight under General de Gaulle (the “Free French” or “Fighting French”). On the other hand, the French Resistance conducted sabotage operations inside German-occupied France. To support the invasion of Normandy of 1944, various groups increased their sabotage and guerrilla attacks; organizations such as the Maquis derailed trains, blew up ammunition depots, and ambushed Germans, for instance at Tulle. The 2nd SS Panzer Division Das Reich came under constant attack and sabotage on their way across the country to Normandy, suspected the village of Oradour-sur-Glane of harboring terrorists, arms and explosives, and wiped out the population in retaliation.
There was also a free French army fighting in the ally, numbering almost five hundred thousand men by June 1944, one million by December and 1.3 million by the end of the war. By the war's end, the French army occupied south of Germany and a part of Austria.
When Allied forces liberated Normandy and Provence in August 1944, a victorious rebellion emerged in occupied Paris and national rejoicing broke out, as did a maelstrom of hatred directed at French people who had collaborated with the Germans (most infamously, the shaving of the heads of French girls who had gone out with German soldiers). Some Germans taken as prisoners were killed by the resistance.
There was debate among the other Allies as to whether France should share in the occupation of the defeated Germany, due to fears that the long Franco–German rivalry might interfere with the rebuilding of Germany. However, it was decided to give the French a share in the occupation, and from 1945 to 1955 French troops were stationed in the Rhineland, Baden-Württemberg, and Berlin, and the areas were put under a French military governor. The Saar (protectorate) was only allowed to rejoin Germany in 1957.
In the 1950s, the French and the Germans finally discontinued the 300-year sequence of committing cruelties against one another, transforming their old enmity and the cycle of revenge into a new period of Franco–German cooperation that led to the formation of European Union. Since then, France and Germany (called West Germany between 1949 and 1990) have generally cooperated in the running of the European Union and also, often, in foreign-policy matters. For example, they jointly opposed the U.S. invasion of Iraq in 2003, leading U.S. Secretary of Defense Donald Rumsfeld to lump them together as “Old Europe”.