The Congress of Aachen [Aix-la-Chapelle] (1818) and the Completion of the Vienna System
By: Randall Lesaffer
The Vienna system, the political and legal order of Europe after the fall of Napoleonic France, rested on two main pillars. If any leading principle could be discovered in the territorial settlement that was reached at the Congress of Vienna in 1815, it was the restoration of the balance of power. The principle was invoked to contain France by strengthening its neighbours to the east—in Italy and Germany—and to the north—the United Kingdom and the Netherlands—and to reorganize the defunct Holy Roman Empire into a confederation of just under 40 states led by Austria and Prussia. The other pillar, which became known as the ‘Concert of Europe’, was an agreement between the four leading powers that had brought Napoleon Bonaparte (1769–1821) to his knees—Austria, Great Britain, Prussia, and Russia—to sustain their alliance against France and jointly assume responsibility for the territorial status quo and the peace of Europe.
The ‘Concert of Europe’ was a continuation of the wartime alliance of the four great powers ranged against Napoleonic France. The Treaty of Chaumont of 1 March 1814 (63 CTS 83) had already provided for the extension for at least 20 years of the wartime alliance into a cooperation to guarantee the future peace against renewed French aggression. After the escape of Napoleon from Elba and his final defeat at Waterloo, the four allies had reconfirmed their alliance in a treaty, signed at Paris on 20 November 1815 (65 CTS 251, French text beginning on page 296, English version in 3 British and Foreign State Papers 273), the same day a new peace treaty was made with France (Second Peace Treaty of Paris, 65 CTS 251).
The Quadruple Alliance was more than a mere guarantee of the territorial settlement of Vienna and an alliance against renewed French expansionism. The negotiations leading to the treaty had once again exposed the fault line that had run through the alliance since the beginning. On the one side stood Russia, seconded by Austria and Prussia, which wanted to turn the alliance into a safeguard against new revolutions in France, or elsewhere in Europe, and claimed a right of intervention to defend the Bourbon dynasty, and by extension other ‘legitimate’ monarchies throughout the continent. In late September 1815, the three eastern great powers had joined in the Holy Alliance, which aimed to promote traditional Christian values and the cooperation of European monarchies as the foundations of the European system (Treaty of 26 September 1815, 65 CTS 199). On the other side stood Great Britain, which wanted to limit its commitments to safeguard the territorial settlement.
This time, however, the events of the preceding months with the return of Napoleon and his invasion of the Southern Netherlands convinced the British that they had to go further. The Quadruple Alliance of 20 November 1815 extended the purview of the alliance to halting a future return of Napoleon to power and protecting the restored Bourbon dynasty against any new revolutions. It stopped far short of claiming a right to intervene against revolutions in other countries, unless those revolutions emanated from France. The leader of British diplomacy, Robert Stewart, Lord Castlereagh (1769–1822), had also agreed to the idea of holding regular meetings among the four powers to discuss their common interests and ‘for the consideration of the measures which at each of those periods shall be considered the most salutary, for the repose and prosperity of Nations, and for the maintenance of the Peace of Europe’ (Article VI). This formed the basis for the system of the so-called ‘Concert of Europe’, whereby the great powers assumed a special responsibility for the solution of conflicts within Europe which pertained to the Vienna settlement and which might endanger the peace among the great powers. France, however, was left out of this conglomerate.
The position of France with relation to the Quadruple Alliance was the true object of contention at the Conference of Aachen [Aix-la-Chapelle], where the leaders of the four great powers convened in late 1818. The official purpose of the meeting was to end the occupation of France, as provided for under Article V of the Quadruple Alliance. While agreement on this was fairly easy, the issue of France’s position in the European system took weeks of difficult negotiations, with Tsar Alexander I (1777–1825) and Castlereagh on opposing sides. Castlereagh found himself in dire straits at home, where parliament had become ever more vocal in its objections to continental commitments.
The tsar opened the round of negotiations with his proposal to include France in the Quadruple Alliance and to make the Quadruple Alliance into an alliance to uphold the Vienna settlement, much as the Quadruple Alliance of a hundred years before (Treaty of 2 August 1718, 30 CTS 415) had united former enemies to guarantee the Peace of Utrecht. Austria and Great Britain, however, resisted this. After this failure, Alexander I stepped up his efforts by proposing a general treaty to which all European powers would accede and which would establish a kind of collective security system for Europe. As this plan also encompassed protection against internal revolutionary convulsions, it was a complete non-starter for Castlereagh. He did not want to go beyond confirming the alliance against France and inviting France to participate in future great power initiatives to aid in the resolution of conflicts between European states.
In the end an agreement was reached after the tsar and the Prussian King Frederick William III (1770–1840) visited the French King Louis XVIII (1755–1824) in Paris, and after a long meeting took place between the tsar and Castlereagh. The Aachen compromise was articulated in two protocols—the term ‘treaty’ was avoided to lessen the risk of rejection by the British parliament. The first protocol, signed 15 November 1818 (69 CTS 369), which remained secret, conformed the military alliance of the four great powers against renewed French aggression or revolution, as contained in Articles I to IV of the Quadruple Alliance. To it a military protocol was added which provided for the deployment of one corps per ally in the Netherlands or Germany. The other protocol, of the same date (69 CTS 365), which had been negotiated with France, allowed France to accede to the system of regular meetings of the great powers, thus including it in the scheme of Article VI of the Quadruple Alliance. Article 4 of the protocol expressly stipulated that invitations to these great power meetings would also be extended to other European states whenever such meetings would have an impact on their affairs. This, however, did nothing to conceal the leading role the five great powers now assumed over matters concerning the peace and stability of Europe.
The non-secret Protocol of Aachen, which was communicated to all European governments, completed the fabric of the Vienna system and the Concert of Europe. In the decades to come, the five great powers would meet on a number of occasions to discuss a common strategy, or lessen the tensions among them, with regard to the many conflicts and convulsions that shook the peace and tranquillity of the continent. Until the Crimean War in the 1850s, no great power war erupted in Europe.
Mark Jarrett, The Congress of Vienna and its Legacy. War and Great Power Diplomacy after Napoleon (London and New York: I.B. Tauris 2013).
Henry Kissinger, A World Restored. Metternich, Castlereagh, and the Problems of Peace, 1812-1822 (London: Weidenfeld & Nicolson 1957).
Matthias Schulz, ‘Paradoxes of a Great Power Peace: The Case of the Concert of Europe’ in Thomas Hippler and Miloš Vec (eds.), Paradoxes of Peace in Nineteenth Century Europe (Oxford: Oxford University Press 2015) 131–52.
Brian E. Vick, The Congress of Vienna. Power and Politics after Napoleon (Cambridge, MA, and London: Harvard University Press 2014).