The Treaty of Versailles was passed in 1919 and formally dissolved the formerly massive Empire of Austria-Hungary (one of the central powers, and losers, of World War One). The territory of Austria-Hungary was divided into smaller independent nations, including Austria, Hungary, Czechoslovakia, and Yugoslavia.

The Peace of Westphalia (1648) is one of the most important treaties in European history. It brought to an end the brutal fighting of the Thirty Years’ War that had devastated the population of German-speaking central Europe and pitted all the major continental powers of Europe against one another. It included formal religious tolerance for all three major branches of Protestantism, including Calvinism for the first time. It provided territorial gains for the Kingdoms of France and Sweden, who both emerged as dominant European powers during this time period. Finally, it provided de jure independence for the territory of Switzerland that had previously only enjoyed de facto independence.

The War of Austrian Succession and the Seven Years’ War both took place during the eighteenth century, whereas the Congress of Vienna took place in 1815, at the beginning of the nineteenth century; therefore, neither of these events contributed to the decline of the “Concert of Europe” in the time period described. The “Concert of Europe” refers to the balance of power implemented in Europe after the Napoleonic Wars designed to preserve peace and the status quo in Europe. It was negatively impacted by the Revolutions of 1848, which encouraged the rise of liberalism and democracy in Europe. It was also negatively impacted by the unifications of Germany and Italy, as two additional major powers emerged on the European scene concurrent with the decline of the Austro-Hungarian Empire.

After World War Two, the governments of France and West Germany wanted to integrate their economies so heavily that a future war would not only be impractical, but an economic impossibility. To this end, they integrated their coal and steel production communities under one umbrella organization. The original treaty was signed in 1951 by six countries: West Germany, France, Belgium, Italy, the Netherlands, and Luxembourg. It can be understood as the first step in the transnationalism that later led to the creation of the European Union.

The Congress of Vienna involved the shifting of Russian and Prussian borders, the confiscation of French territory gained after 1789, a guarantee of neutrality for Switzerland, and the general balance of power in Europe. King Charles X of France was not overthrown until the July Revolution of 1830.

The Treaty of Lausanne, signed in 1923 in Switzerland, ended the conflict between the Ottoman Empire and the World War I Allies. The Turks ceded much of the Ottoman Empire's territory in exchange for the Allies recognition of Turkey as a sovereign republic.

Germany lost Silesia, its colonies, its legal right to a substantial military, and was forced to sign the War Guilt clause of the Treaty of Versailles, which resulted in the discrediting of the German political left. While no Allied garrisons were established, France and Belgium would later occupy the Ruhr valley in 1923 to extract reparations.

Austria regained the Tyrol, Salzburg, the Illyrian Provinces and Lombardy-Venetia, among other territories. Prussia gained Westphalia, Danzig, and much of Saxony, while dividing the Duchy of Warsaw with Russia, which also was allowed to keep Finland. Britain was confirmed in control of the Cape Colony. Each of these countries was a major power during the Napoleonic Wars and a victor in the War of the Seventh Coalition which defeated Napoleon at Waterloo in 1815. Belgium, however, was retained in the Kingdom of the Netherlands and did not gain its independence until 1830.

Woodrow Wilson saw the United States through World War I and during that time he developed his famous “Fourteen Points.” These were things that he wanted to see accomplished when the war was over that he felt would bring about peace. Wilson believed that it was critical to establish an international organization of countries to foster greater dialogue and cooperation. Wilson believed that this organization would be key to preventing future wars and conflicts. While the League of Nations was established, the United States was never a member as the Senate refused to ratify the treaty. The lack of the United States contributed to the League of Nation’s lack of effectiveness. It was eventually replaced by the United Nations.

The Treaty of Portsmouth ended that Russo-Japanese War, which lasted from 1904 until 1905 and was fought over Russia’s expansion into East Asia. The established Russian Empire was picked to win the conflict, but Japan surprisingly found military success and fought well against the Russians. This conflict was Japan’s entrance onto the world stage and established the nation as a future world power. This conflict was very unpopular in Russia and contributed to the frustration of the Russian people with the Tsar. President Theodore Roosevelt helped bring about a peace agreement by working with Japan and Russia and getting their diplomats to meet in Portsmouth, New Hampshire to settle the conflict. Roosevelt won the Nobel Peace Prize for his efforts in bringing about this treaty.