Though Napoleon's empire remained politically intact, however, strains began to show. Napoleon's conquest of Europe, the burdens of the Continental System and the British blockade, and the high taxes Napoleon levied outside of France led to resentment and resistance in many regions of the Empire. People were becoming tired of seeing their nations used as pawns against the British. Thus, nationalism developed in reaction to Napoleon's imperial reign.
The main site of anti-Napoleonic nationalism was in the German states, some of which had been absorbed by France, but most of which were in the Confederation of the Rhine. The German nationalist movement rebelled not only against French rule, but against the entire French intellectual tradition. The years of French domination saw a remarkable flowering of thought and art in Germany, with philosophers and artists such as Goethe, Schiller, Herder, Kant, Hegel, and Beethoven rising to the fore.
Against the dominant tradition of French Enlightenment Rationalism that underlay the entire Napoleonic empire and its rules, German intellectuals now began a revolution in thought called Romanticism. Romanticism challenged nearly every aspect of French Rationalism. Since the French Empire was built on French Rationalism, the policies of the empire came under attack. The Enlightenment idea of universal laws that applied to everyone came under attack.
J.G. Fichte, who drew on the work of J.G. Herder(discussed in Commentary, below) was a German philosopher and Romantic who argued that each person's inner self determined their morality. In 1800, Fichte proposed a "Closed Commercial State", advocating a centralized state that could isolate itself from the world to develop its own volksgeist, a word describing a nations distinct sense of self. When Germany fell under French domination, Fichte argued (like Herder) that there was a special German "spirit". Unlike Herder, Fichte claimed that the German spirit was better than that of other nations, and for that reason, it needed to be carefully protected from being perverted by contact with outside influences, such as the French influence.
Thus, Napoleon's domination of Germany helped propel both a political and intellectual reaction, fueling the growth of German Nationalism and Romanticism.
Before the Napoleonic era, Germany had never had much of a national identity; it consisted only of the loose grouping of states united only by a common language, vague cultural ties, and the weak government of the Holy Roman Empire. The envy inspired by French power instilled in the Germans a desire to revitalize their own political system and to gain a unifying national consciousness. Politically, the French Revolution demonstrated to the Germans the power of nationalism to mobilize people. The liberal reforms of the French Revolution led to a more efficient French system and a more patriotic French population. As seen in the reforms of Prussia, the Germans followed suit. Socially, French domination of culture and thought created a sense in Germans that they needed to construct their own sense of nationalism. Many Germans emerged from Napoleonic rule tired of the petty kingdoms and principalities that made up the Holy Roman Empire, and they hoped for a unified state. For the most part, they looked for leadership to Prussia, a modernizing state on the eastern fringes of what at this time was the traditional "German" heartland (described in more detail next section.
The nationalism that developed in reaction to Napoleon usually took one of two tracks. In some cases, it was a conservative nationalism, a desire to go back to the old ways that prevailed before Napoleon took over and started making reforms. On the other hand, there was also a liberal nationalism. Napoleon brought European countries some of the fruits of the French Revolution, but some people wanted more: they wanted true self-government. Amazingly, opposite approaches, liberal and conservative, worked in tandem to oppose Napoleon's rule.
Romanticism and German Nationalism both have their roots in the work of J.G. Herder. In 1784, he published Ideas on the Philosophy of the History of Mankind, in which he suggested that every nation was different, and that every nation had its own particular specialty (of "genius"). By this logic, Germany should not copy France, but pursue its own particular national genius and identity. Herder invoked the Volk (the people) as the root of the true national culture and special nature (Volksgeist) which every nation should try to express. Herder did not mean his ideas to apply only to Germany, but to all nations. Herder's ideas were radically at odds with ideas of Enlightenment philosophes like Voltaire who believed that all nations would follow similar paths of progress from barbarity to civilization, though at different rates. Herder's ideology of differences in national Volksgeist from country to country would spread throughout Europe, counter to the French idea that all countries and peoples are basically the same and would benefit by the same kinds of "progress". Ideas such as what constituted "good" art or literature were challenged, because art might not apply to everyone in the same way. By Herder's way of thinking, art was good only inasmuch as it represented a particular Volksgeist. The implication of this way of thinking is that the concept that there were certain good universal laws, a cornerstone of the French Revolution, was challenged in Germany.
Britain was also strongly swept by anti-Napoleonic nationalism. The years of Napoleonic rule were also crucial years in the development of British manufacturing through the Industrial Revolution. British workers were being horribly exploited, working long hours at monotonous and dangerous jobs for little pay. Unemployment was high. A workers' revolt might well have happened if the British people hadn't had Napoleon to rally against. Opposition to Napoleon unified Britain, and may be one factor explaining why workers didn't revolt against the factory system in this still early, fairly oppressive stage of the Industrial Revolution.
Two exceptions to the general rule that French dominance created local nationalism were Italy and the Grand Duchy of Warsaw. The Italians, lacking a unified history and broken into several states under Napoleon, never developed a strong anti-Napoleon nationalist movement. The Poles were also quite happy with their new, restored state. Even if it wasn't really independent, at least they had a state, rather than being split up and controlled by Russia, Prussia, and Austria, which was what would likely happen if Napoleon hadn't been supporting the Grand Duchy.