In foreign politics, in the earlier part of the nineteenth century, during the Napoleonic wars, Prussia, as yet hardly recovered from her defeats under Buonaparte, almost entirely followed the lead of Austria. But perhaps the most important measure of the Prussian Government at this time was the foundation of the famous Zollverein or Customs Union of various North German States in 1834. The far-reaching character of this measure was only shown later, being, in fact, the means and basis by and on which the political and military ascendancy of Prussia over all Germany was assured. Friedrich Wilhelm III, who died on June 7, 1840, was succeeded by his son, Friedrich Wilhelm IV. The new reign began with an appearance of Liberalism by a general amnesty for political offences. Reaction, however, soon raised its head again, and Friedrich Wilhelm IV, in spite of his varnish of philosophical and literary tastes, was soon seen to be _au fond_ as reactionary as his predecessors. The conflict between the reaction of the Government and the now widely spread Liberal and democratic aspirations of the people resulted in Prussia (as it did under similar circumstances in other countries) in the outbreak of the revolution of 1848. It is necessary at this stage to take a brief survey of the political history of the Germanic States of Europe generally from the time of the Peace of Vienna, in 1815, onwards, in order to understand fully the role played by the Prussian monarchy in German history since 1848; for from this time the history of Prussia becomes more and more bound up with that of the German peoples as a whole. During the Napoleonic wars Germany, as every one knows, was, generally speaking, in the grip of the French Imperial power. To follow the vicissitudes and fluctuations of fortune throughout Central Europe during these years lies outside our present purpose. We are here chiefly concerned with the political development from the Treaty of Vienna, as signed on June 9, 1815, onward. The Treaty of Vienna completed the work begun by Napoleon--represented by the extinction of the mediaeval "Holy Roman Empire of the German nation" in 1806--in making an end of the political configuration of the German peoples which had grown up during the Middle Ages and survived, in a more or less decayed condition, since the Peace of Westphalia, which concluded the Thirty Years' War. The three hundred separate States of which Germany had originally consisted were now reduced to thirty-nine, a number which, by the extinction of sundry minor governing lines, was before long further reduced to thirty-five. These States constituted themselves into a new German Confederation, with a Federal Assembly, meeting at Frankfurt-on-the-Main. The new Federal Council, or Assembly, however, soon revealed itself as but the tool of the princes and a bulwark of reaction.