The Peace of Westphalia concluded the Thirty Years War, ending conflict among most of the major European states as well as many kingdoms of the Hapsburg Empire. 

President Woodrow Wilson's 14-point plan, which he presented to the assembled statesmen at the Peace of Paris following World War I, included such points as freedom of the seas, freedom of national self-determination, the guarantee of Belgian sovereignty, and a proposal for the League of Nations. It did not, however, include a proposal for the Marshall Plan, which came in the aftermath of World War II.

The League of Nations, conceived as part of Woodrow Wilson's 14-point plan, was partly intended to prevent global scale violence from breaking out again. It failed in this duty, given the rising tensions of the interwar period and, finally, the outbreak of global war again in 1939.

After the Napoleonic Wars were over an Austrian politician, Klemens Wenzel von Metternich, hosted a meeting of the major powers of Europe to decide how the redraw the map of Europe so as to avoid further wars like the Napoleonic Wars, which had brought Europe to the point of exhaustion.

The Congress of Vienna was meant to stabilize Europe by surrounding France with several powerful nations, thus discouraging them from attempting large scale military invasions like they had in the Napoleonic Wars.

The Edict of Nantes sought to end the religious wars by separating religion from public life. The reasoning behind the Edict was that if protestants and Catholics were both allowed the same universal rights regardless of religion, a secular society could be built in the aftermath of the protracted, bloody religious conflict.

The Berlin Conference and Russian Revolution both took place before the League of Nations was created. It didn't prevent the collapse of the Weimar Republic and many historians think that the lack of American support weakened the League. However, the League did emerge out of the peace following World War I.

The union of Lublin unified the two nations of Poland and Lithuania into one nation under the Jageillonian Dynasty

The Holy League was set up by nearly all of the nations in Europe that neighbored the Ottoman Empire as a joint military force with the purpose of warding off attack by the Ottomans.

The Union of Kreva saw the marriage of the Grand Duke of Lithuania to the daughter of the recently passed Polish king. Jadwiga had no brothers so she was crowned King of Poland, set to rule until she married. Her mother then arranged a marriage with the leader of Lithuania, the Grand Duke Jogalia, thus joining the royal lines of Poland and Lithuania.