When the Quadruple Alliance, along with representatives of minor powers, met together at the Congress of Vienna they combined leniency toward France with strong defensive measures. The Low Countries — Belgium and Holland — were united under an enlarged Dutch monarchy capable of opposing France more effectively. Prussia received considerably more territory along France’s eastern border to stand as a “sentinel on the Rhine” against renewed French aggression. At the same time, France did not have to pay any war reparations and it did not lose large amounts of territory.

In their moderation toward France, the allies were motivated by self-interest and traditional ideas about the balance of power. To the peacemakers, especially to Klemens von Metternich (1773–1859), Austria’s foreign minister, the balance of power meant an international equilibrium of political and military forces that would discourage aggression by any state or combination of states. The Quadruple Alliance members, therefore, agreed to meet periodically to discuss their common interests and to consider appropriate measures to maintain peace in Europe. This agreement marked the beginning of the European “congress system,” which lasted long into the nineteenth century.