The congress of Vienna that started in September, 1814, and ended in June, 1815, aimed to equilibrate the powers of Europe in order to avoid future disputes. The creation of new interior borders in Europe provided the state of equilibrium between these great powers.
The fall of Napoleon led to the return to the old order of Nations. The restoration of the prior political divisions of Europe was mastered by the Austrian Foreign Minister Metternich. The consequence of the treaty, established by the Metternich, empowered Great Britain to hold the equilibrium of powers.
It was obvious that the reinstatement of the legitimate rulers was possible only if the rulers served the interests of the Great Powers. Hence, the Bourbon dynasty was reinstated in Spain, while the Bourbons of France were replaced.
Central Italy was kept under the influence of Austrian power through the reinstatement of the prince of Hapsburg. Central Europe gained strength against France and Russia kept Finland and a large part of Poland.
Although the Vienna Congress Treaty tried to deracinate the ideas of liberalism and nationalism, after 1815, these two forces led to many revolts, in Spain, in the Italian states and in Belgium.