The Balance of Power from the Thirty Years’ War and the Peace of Westphalia (1648) to the War of the Spanish Succession and the Peace of Utrecht (1713)

ABSTRACT The balance-of-power idea became a crucial concept in the discourse of international affairs by the mid-seventeenth century. Nonetheless, the concept of balance of power was not even explicitly referenced in the Peace of Westphalia (1648). Instead, the legal principles of status quo ante and uti possidetis reigned supreme. Even though the balance-of-power principle was not mentioned in the Peace of Westphalia, it was often referenced during the negotiations and its implicit presence or practical balance of power was evident in the treaties trying to reach stability in the inter-state system. Several alliances, concluded mostly against France and Louis XIV in the second half of the seventeenth century, implied the balance of power and, more specifically, the balance of sea power. The paper argues that the balancing process became less theoretical and more pragmatic as evidenced by interactive alliance treaties that established reciprocal responsibilities and numerical equilibrium. By the Peace of Utrecht (1713), the balance of power or the balance of Europe became a leading principle and it was referenced repeatedly in the treaties in different languages. The paper traces the balance-of-power idea from the diplomatic background to the diplomatic foreground as the idea moved from natural law to positive law.


Introduction
The balance of power was one of those infamous principles that evaded a simple and clear definition. Emmerich de Vattel understood the balance of power as 'such a disposition of things, as no power is able absolutely to predominate, or, to prescribe laws to others.' 1 Although this definition is broad and vague, it perfectly represents the broad and vague interpretations of balance of power, which had as many definitions as there were writers writing about it. 2 According to Vattel, 'Europe forms a political system, a body … and the perpetual negotiations make Europe a kind of a republic, … through the ties of common interest, for the maintenance of order and liberty. Hence arose that famous scheme of the political equilibrium or balance of power.' 3 This paper does not delve deeper into the different definitions of the balance of power, but it highlights its discourse value, its international spread and its growing importance in the long seventeenth century.
The balance-of-power idea became the habitus of diplomacy and inter-state system by the midseventeenth century. 4 The Peace of Westphalia has become a reference point in the history of second half of the seventeenth century and the main conflicts and their resolutions. The balance-ofpower idea was used extensively and in a growing number of (anonymous) political pamphlets, but it was still not used in any major international treaty. The third part presents the War of the Spanish Succession and the Peace of Utrecht, where the balance-of-power idea was explicitly noted as a fundamental principle and the reason for the peace treaty. The balance-of-power idea became referenced even in such 'mundane' or quotidian forms of political discourse as newspapers. I argue that the balancing was subject to numerical assessment which was manifested in interactive alliance treaties trying to reach just reciprocal responsibilities.

The Thirty Years' War and the Peace of Westphalia
The concern for the 'European equilibrium' already framed the discourse around the outbreak of the Thirty Years' War. Several 'foreign' noble heads were circulating as the potential successors to the childless Emperor Matthias. In 1617, an anonymous French pamphleteer recognised the perspectives of each dynasty in Europe and deduced that the balance was the best option. Thus, he rejected the thought that the young Louis XIII should seek the imperial sceptre. He should, however, seek to transfer it to another European dynasty and not let it stay in the hands of the Habsburgs. Through such selfless act, Louis XIII 'would become the arbiter of all and would hold the balance of the world in his hands, which he received from Heaven.' 10 Richelieu and Louis XIII argued that the latter had become the 'arbiter of Christendom' (arbitre de la chrestienté). 11 With this 'balance,' the pamphleteer implied that Louis would follow Justice and act equitably.
Predictably, less and less thinkers assigned the leadership role to the Pope. Although Pope's authority was far from firm even at the height of the medieval respublica Christiana, it even lost its symbolic unifying power in Europe after the Reformation. The above-mentioned anonymous French pamphleteer claimed that the Pope should 'respect the equality of rulers and the counterweight of affairs more than the extent of great and eminent supremacy.' 12 Similar opinions started to appear even from inside the Church. Xantes Mariales, a Dominican theologian from Venice, noted that the Pope 'certainly should have seen the nations balanced and the scales adjusted.' 13 This was an interesting transition period: the balance-of-power idea was gaining ground while the idea of the common Christendom under a single religious leader was losing ground. Thus, the idea of stability through the balance of power in the inter-state system overshadowed the idea of peace through one (universal) empire.
Although the religious concerns were not unimportant, the justification for the entry into the 'German war,' by both the Swedish and French crowns, was the protection of the (German) princes from the aggressions of the Emperor who was assisted by the Spanish king. Furthermore, any fortification of the Habsburgs inside the Empire would also endanger polities outside the Empire, as claimed by their opponents. This was clearly spelled out in the broadly disseminated war manifesto by Gustavus Adolphus of Sweden, written by his councillor Johan Adler Salvius and published anonymously. 14 Salvius accused the Habsburgs of plotting a 'universal monarchy' and the subjugation of Europe. Even during the peace negotiations in the 1640s, the same claims against the Habsburg designs for 'universal monarchy' were propagated by the Swedish and French diplomats. 15 Likewise for France, Henri de Rohan pointed out that if Spain gained power, it was natural that France needed to grow. He noted that 'there were two powers in the Christendom,' both France and Spain were as 'two poles' (come les deux Poles) which must be balanced in the emerging inter-state system. 16 This Spain-France dialectic was still characteristic for the first half of the seventeenth century. Ironically, his balancing theory which was established to argue against the Spanish hegemony would later be used to argue against the French hegemony. As is clear from contemporaneous private texts, the true reasons were more self-interested. Even before the French entry into the Thirty Years' War in 1635, Richelieu wrote a confidential memorandum in 1632 to argue for the direct intervention of France. He wanted 'to ruin the House of Austria completely, … to profit from its dismemberment, and to make the [French] king the head of all the Catholic princes of Christendom and thus the most powerful in Europe.' 17 The Habsburg side responded in kind. After France entered the war in 1635, Wunifried Alman von Warendorff wrote a pamphlet for the Habsburgs. He accused France of religious hypocrisy, warmongering and egoistic behaviour, especially after the 'house of Austria' had already signed the Treaty of Regensburg (1630) and the Peace of Prague (1635). Alman pointed out that 'the French desire to rule over the whole world and so bring all people under their control, because they themselves orally and in writing stated that Charlemagne's Monarchy belongs to them.' 18 Thus, Warendorff noted that all states should unite against France which seeks universal monarchy. The position of hegemon or major threat during this war oscillated between Spain and France. To preserve European balance and peace, cooperation was needed and, eventually, an agreement was reached in 1648.
The Peace of Westphalia was not a pan-European charter. 19 The two main documents were the Treaty of Osnabrück (IPO) between the Holy Roman Empire and Sweden, and the Treaty of Münster (IPM) between the Holy Roman Empire and France. 20 The treaties mention neither the regional German nor the European balance. Moreover, no contemporaneous translation in other European languages included the phrase or even the word balance itself. The key cause for the treaty was 'publick Tranquillity' (publicae tranquillitatis causa), 21 and several commemorative medals show the allegorical figure of Peace holding olive branches in her hands ( Figure 1). The majority of the articles dealt with mutual restitutions between polities and religious agreements between the Catholics and the Protestants. However, this is not to say that the balance-of-power idea was not implicitly present in the treaties.
Instrumentum pacis Osnaburgensis (IPO) was written with two fundamental principles of international law in mind: status quo ante (bellum) and its 'opposite' uti possidetis (ita possideatis). 22 Thus, the key verbs and phrases used in the treaty were 're-established', 'restored to that state', 'in the same state they were before these Troubles', 'to remain in the state they are in at this present', etc. 23 These two legal doctrines are, however, in contrast to the balance-of-power idea which often demands constant changes and adaptations. While status quo ante and uti possidetis provide some sense of stability, the balance-of-power idea requires flexibility. Even the durability of 'perpetual Peace' (pax perpetua) stated in the disposition of the treaties could be seen as going against the balance-of-power idea. The balance of power was implicitly felt in the articles connected with the arrangement of religious issues and relied on natural law. Even here, however, they referenced the previous treaties such as the 'Transaction settled at Passau in the Year 1552. and follow'd in the Year 1555. with the Peace of Religion.' Nonetheless, IPO also advocated for 'an exact and reciprocal Equality amongst all the Electors, Princes and States of both Religions' (inter utriusque religionis electores, principes, status omnes et singulos sit aequalitas exacta mutuaque), and 'all other Officers shall be equal in number in both Religions' (omnes sint aequali numero utriusque religionis). 24 Thus, the idea that equality, parity or balance between the confessions provided a better solution than the return to the 'previous state' was implicitly present in the understanding of the balance as the 'equal' distribution of power.
The equality or the balance of the three confessions, 'the Catholic, the Augsburg, and the Reformed,' 25 was in the background of these articles. IPO was based on the Peace of Prague, where the 'equality of religion' was mentioned explicitly (Gleichheit der Religion). 26 The statesmen and diplomats considered the numerical distribution of power or positions between confessions to be key for peaceful co-existence. Moreover, if the number of positions was odd, then the extra position would shift 'alternately every year' (alternando singulis annis) between Catholics and Protestants. 27 In connection to this, the complex concept of 'Landeshoheit' (superioritas territorialis) or territorial sovereignty was a key political factor in the building of the German political balance of power. However, since Sweden and France entered the war, the internal religious issues cannot be strictly divorced from early modern inter-state politics and the general balance of power in Europe.
In Instrumentum Pacis Monasteriensis (IPM) between the Holy Roman Emperor and the 'most Christian' (French) King, 'the Republick of Venice is therein compris'd as Mediatrix of this Treaty.' 28 At Münster, Venice served exclusively as mediator between the Catholic powers (ambassador Contarini), as did the Pope or his ambassador, i.e. nuncio Chigi; there was no mediation between the Protestant powers in Osnabrück. At the time, Venice was also probably considered as mediator because of its 'tolerant' attitude to all confessions and because it was one of the few countries that maintained neutrality throughout the Thirty Years' War. Even Émeric Crucé, the French monk and mathematician, in his utopian pacifistic proposal chose Venice as the seat of the assembly of ambassadors of all countries, both European and non-European, where urgent issues would be resolved peacefully. 29 However, despite the balance of power or the word balance not being used in the treaties themselves, it was part of the diplomatic discussions during the Congress of Westphalia in the 1640s. It was referenced several times as balance in the French and Swedish correspondence and instructions, as balancer, ballance and équilibre in the French correspondence, as Gleichgewicht, abwägen and ausgleichen in French, Swedish and German correspondence (also as Gleichgewicht der Kräfte). 30 Thus, the balance-of-power idea came forth as part of a discourse on the political order in Europe, but it could not dethrone the alternative legal principles of status quo ante and uti possidetis. The balance was not yet turned into a strictly legal concept. International law gradually started to emancipate itself from natural law. 31

Forming Alliances and Making Treaties (against France)
After Westphalia, the balance of power tilted in France's favour and Louis XIV eventually took over the role of European aggressor and hegemon. At the same time, the European 'public' support shifted from France to the Habsburgs. According to Ernest Nys, the Peace of the Pyrenees (1659) between France and Spain, and not the Peace of Westphalia, formed a foundation for international law until the French Revolution. 32 Considering the importance for France which became the prime European superpower in the 1660s, this might well be the case. Among other things, in relation to trade and commercial affairs, the Pyrenean Treaty dictated 'that the equality shall be mutual, in all manner, on both sides.' 33 This equality is, of course, not to be equalled with the balance of power; it could be interpreted as the balance of trade.
The ambition of Louis XIV gave rise to new anti-French alliances as France was now perceived as a 'perpetual' threat to the European inter-state system. Louis XIV was sometimes called the 'European Turk,' 34 or 'French Attila,' 35 on the grounds of his aggression. This rhetorical device was often used against any opponent who supposedly broke European jus gentium or, as Carl Schmitt later called it, jus publicum europaeum. 36 Three major wars, in which France played the offensive role, followed in rapid succession: the War of Devolution (1667-68), the Franco-Dutch War , and the War of the Grand Alliance or the Nine Years' War (1688-97). These wars were also incentives for the international discourse around the balance-of-power idea.
The expansive tendencies of Louis XIV encouraged thinkers to think about the nature of balance and it became the mainstream of European political discourse. The most prominent Habsburg jurist and diplomat François-Paul de Lisola wrote Bouclier d'Estat (The Shield of State) in 1667; it was translated into English the same year. He directly referenced Henri de Rohan, but noted that it was France, not Spain, which posed the danger to the 'European balance.' Lisola accused Louis XIV of trying to attain the 'universal monarchy' while simultaneously accusing the Habsburgs of these same 'universal' aspirations. Lisola stated that European statesmen should form a strong anti-French alliance and keep the balance between France and Spain, if they wanted to maintain their autonomy and preserve peace in Europe. 37 Lisola's 'balanced' ideas were one of the reasons for public opinion to shift from anti-Spanish to anti-French. Lisola's stay in England in 1666-68 and his texts were crucial for this anti-French shift in England. 38 In 1668, Slingsby Bethel published a pamphlet that criticised Oliver Cromwell. When in 1655 he went to war with Spain, instead of France, Cromwell 'broke the balance betwixt the two Crowns.' 39 Bethel argued that Cromwell did not follow the common sense of always going against the most powerful, which was, at the time, already France. He wanted an adaptable and dynamic foreign policy with no fixed alliances or antagonisms. Bethel directly criticised Cromwell but indirectly Charles II who supported Louis XIV. 40 Bethel pointed out that because England was not strong enough to oppose France alone, it should seek alliances to maintain balance. This idea of the shift in international power politics was constantly reverberated in pamphlets in the next decades.
This political discourse and such pamphlets affected politics and parliamentary pressure forced Charles II into the Triple Alliance of 1668 with Sweden and the Netherlands. The Triple Alliance wanted to check the universalist claims of France after France had initiated the War of Devolution (1667-68) and occupied large parts of the Spanish Netherlands. Spiritus agens and the architect of the Triple Alliance was the experienced English diplomat William Temple who went against his king's overt pro-French stance. Temple warned the king about the danger of a too powerful France for Europe. The Triple Alliance treaty never explicitly mentioned France, but the message was clear. The potential power of these three allied states and Spain was enough of a warning to pressure Louis XIV to pull back.
The balance-of-power discussions still mostly took place in the diplomatic background as evident from the contemporaneous correspondence. The Grand Pensionary of Holland Johan de Witt and Temple traded a few friendly letters talking about the alliance and the mutual 'reasonable equality' (egalité raissonable), which they considered to be a 'true foundation of goodwill and friendship' (vray fondement de bienviellance et d'amitié). 41 Temple clearly saw the balance of power at work within the wider system of European states. This phrase in connection with the balance of power would almost verbatim appear in the second article of the Treaty of Utrecht in 1713, which just shows how commonplace the phrase was becoming.
However, the implicit balance of power mechanism was also coming to the foreground in this alliance treaty. The Triple Alliance or the 'perpetual Defensive League' was designed to prevent any future conflicts and limit French ambitions. In the publicly printed and published treaty, they specified how many soldiers, horses, warships and guns each of them would put forward in the case of emergency. The Dutch Republic and England had to contribute the equal number of troops and resources, and both had 'to assist … with forty Ships of War well equipped, of which 14 to carry between 60 and 80 Guns, and 400 men apiece one with another (18.000 pounds/ month).' 42 Such an alliance served as a deterrent to Frenh expansion and a guaranty for peace. 43 This is a clear example of how they numerically tried to assess the just and balanced contributions of each allied state, forming the balance of sea power (Figure 2).
Despite Temple's efforts, in 1670, Charles II and Louis XIV signed the (Secret) Treaty of Dover, forming an alliance aimed against the Netherlands. In the fifth clause, they decided 'to declare and wage the war jointly with all their forces by land and sea … to reduce the power of a nation which … even has the insolence to aim now at setting itself up as sovereign arbiter and judge of all other potentates.' 44 Thus, the reason for the (Franco-)Dutch war (1672-78) declared by the French First Minister of State Jean-Baptiste Colbert was the quarrel over the 'sovereignty of the seas' and the 'Dutch ingratitude.' 45 Despite its small size and population, the Netherlands was suspected of craving a universal maritime and commercial empire during the 1660s and early 1670s. 46 Figure 2. The Dutch allegorical drawing of the Triple Alliance. Depicted were Charles II, Johan de Witt and Charles XI of Sweden holding hands. Warships were at anchor in the background to ensure the balance of (sea) power in Europe.
Many pamphlets implying a balance of power were written during the Third Anglo-Dutch War (1672-74) as the English public and parliament opposed the war. 47 A pamphlet by the 'English Presbyterian' in 1672 noted that 'the Peace of England depends on the peace of Europe and this peace depends on the perpetual opposition between Spain and France.' 48 So, the goal was not just peace but a balanced and perpetual opposition between Spain and France. Similar to Lisola, many English pamphlet writers emphasised the role of England as the holder of the balance; 49 e.g. an anonymous writer stated that 'in this dangerous Crisis of Affairs, it has pleas'd Divine Providence to leave England the Arbitresse of the Fate of Europe.' 50 Moreover, in 1673, Lisola published 'an appeal to England', written in French, and called on England to join the new anti-French alliance to reset the balance in Europe. 51 This anti-French alliance already included the Empire, Spain, Brandenburg-Prussia and Denmark-Norway.
After England signed the (separate) Treaty of Westminster (1674) with the Netherlands, it broke the 'artificial' alliance with France. 52 In the Epistle to the Reader, Andrew Yarranton warned that 'the great danger might ensue in breaking the Ballance of Europe, it being then so indifferently settled.' In relation to France continuing the war with the Netherlands, he considered 'the Balance … now broke.' 53 He concluded that although the Dutch were England's primary trade rivals, Europe should rally against Louis XIV during the Dutch War to reset the balance. After William of Orange married the niece of Charles II, Mary, England joined the defensive alliance with the Dutch in March 1678. France was again 'forced' to diplomacy.
A series of treaties known as the Peace of Nijmegen were signed in September of the same year. 54 Here, again, the verb to restore, in reference to several previous treaties, reigns supreme. In an earlier alliance treaty between England and the Netherlands signed in July 1678, both states consented in the second article to act 'with all their united force,' but the former 'shall furnish one third more by sea than the States [of Holland], and they one third more by land than his Majesty.' 55 This just proves how practical and interactive the manifestation of the balancing process had become by that time. Since the Dutch had to direct their defensive capabilities to land to counter the French onslaught, they now needed to provide one third less maritime forces, and one third more military forces.
These numerical analyses of power distribution and alliances were also the result of the new definition of power. If the old potestas implied domination in a relationship to another body, the new potentia meant only capacity in a relationship to the whole world in a form of harmony. In the Tractatus Theologico-Politicus (1670) and Tractatus Politicus (1677), Baruch Spinoza talked about the 'pooling' of powers that forms a civil society. His concept of ordered distribution, based on his theological theories, is critical to his understanding of power. For potentia was distributed in line with a certain and determinate order and can only be appropriately analysed when this is appreciated. 56 The system or the body politic is thus under constant stress to keep the proper balance and harmony. Spinoza was part of the movement that wanted to implement the geometrical method or the 'method of Euclid' in philosophy. 57 In this sense, the influence of the Scientific Revolution is clear. The geometrical method was not just used in sciences, such as mathematics, astronomy and physics, but also in philosophy and law. Since the terminology of balance was taken from the old static physical sciences, there was a tendency to see the alliances as static, but by the end of the seventeenth century, it was replaced by a more complex idea. Isaac Newton's famous Laws of Motion best synthesise the effect of balanced and unbalanced forces. Newton's First Law states that a body at rest will remain at rest unless acted upon by an external and unbalanced force, and a body in motion will remain in motion unless acted upon by an external and unbalanced force. 58 This law is also called the Law of Inertia or Galileo's principle, but it actually occurs in many other natural philosophers even before Newton and Galileo; it was experimentally demonstrated only during the seventeenth century. 59 Thus, external factors exerciseor nota force over a body and determine the balance or the unbalance of a system.
Balance-of-power discussions persisted in peacetime as well. In 1680, another Anglo-Dutch defensive alliance argued 'to keep the Balance of Europe from being called back into a Chaos, out of which the French may form a Universal Monarchy.' 60 The Marquise of Halifax, George Saville, was anti-French not out of ideological but out of pragmatic reasons. In his texts, he claimed that France succeeded Spain in claiming hegemony, and that England should oppose the French aggression now just as England opposed Spain a hundred years ago. 61 Halifax realised the mechanism of fighting against the shifting superior superpowers, so today's ally could become tomorrow's enemy. Similarly, Gottfried Wilhelm Leibniz wrote a satire about Louis XIV's designs for universal monarchy with an ironic title. 62 The balance of power was also addressed by the jurists. Samuel von Pufendorf wrote his magnum opus in London where the idea was widely 'praised.' However, in expounding of Grotius's stance on the (un)just causes of war, Pufendorf was also sceptical about the notion of a just preventive war on the basis of balance against a powerful state. At least the undeniable evidence for the potential aggression or an unusual increase in a neighbour's power should be clear, although even such excuse for war may be called 'unpardonably impudent.' 63 Pufendorf's formulation was similar to the later Caroline test stating that 'the necessity for action must be instant, overwhelming and leaving no choice of means and no moment for deliberation.' 64 The question of pre-emptive self-defence was often on the minds of legal scholars in the early modern era when thinking about the balance of power.
Following such texts, the majority of European states consciously developed the politics that followed the balance-of-power idea, especially in relation to alliance building. In 1688, Louis XIV decided for the invasion of the Rhenish Palatinate (sac du Palatinat) and started the Nine Years' War (1688-97). The next year, the (first) Grand Alliance between the Netherlands, Spain, Bavaria, England and Austria was formed to limit France. This time, however, France was too strong to back down, and the allied states were also involved in other wars, e.g. the Jacobite rising of 1689, the Williamite War in Ireland, and the Great Turkish War or the Wars of the Holy League against the Ottoman Empire.
The balance of power was behind the formation of the (first) Grand Alliance. Only ten years after the unequal distribution of responsibilities, the balance of sea power got back to the equal distribution. In the first article of a special alliance treaty 'concerning the fitting out a Fleet,' both states divided the naval burdens equally and each 'shall send to Sea fifty large Men of War, viz. one Second Rate, seventeen Third, and thirty-two Fourth Rates, with fifteen Frigates and eight Fireships … ' 65 The personal union between Great Britain and the Netherlands proved detrimental for the latter since the large expensive campaigns were mostly paid for with Dutch funds. After a few decades, the Netherlands was financially exhausted, and the main Dutch banking houses and trading gradually moved from Amsterdam to London. 66 Such interactive 'balancing' was echoed by Thomas Manley. Previously, rulers 'maintain'd the power of Christendom in an equal Ballance, dexterously throwing their Arms into that Scale which appeared lightest, knowing they secured thereby their own Peace, and Government.' Manley even tried to put such politics further back in the past and 'invented tradition' by describing the 210-years of English rulers who followed this 'fundamental Interest of Princes.' However, according to Manley, this was not enough anymore, as long 'as the just balance is so much ruined' and France threatened Holland. If Holland fell, England would soon follow because it was too weak to confront France alone. Thus, an offensive preventive war with France was necessary to ensure the 'Ballance of Christendom.' 67 In accordance with Nys's thesis that the hegemon in Europe produced fewer balance-of-power texts, France was the target of criticisms of other 'foreign' balance-of-power writers. 68 Solange Rameix comparatively examined the significance of the pulpit for war propaganda in the 1690s, especially in relation to the Nine Years' War. She found out that, in fact, the French crown was much less concerned to justify its actions, in contrast to the regime of William III, which sought legitimacy using the argument of just war. 69 Thus, the relative lack of (published) French texts or discourse revolving around the balance testifies to France's superior position at that time.
However, this is not to say that the educated French did not privately disseminate the balance-ofpower ideas. In the posthumously published instructions on the royal duties, François de Fénelon also propagated the alliances that would maintain balance in Europe. In contrast to other writers though, he did not want other states to acquire too much power to threaten France: 'To hinder one's neighbor from becoming too strong is not to do harm; it is to guarantee one's self and one's neighbor from subjection; in a word it is to work for liberty, tranquility, and public safety … This attention to the maintenance of a kind of equality and equilibrium between neighboring states is what assures peace for all.' 70 The role of public opinion mattered more and more, and many pamphlet writers explicitly referenced the balance-of-power idea. Peter Pett stated that 'we shall be forced still to look out sharp to keep the ballance of Power exact in the whole World abroad.' 71 William III, similar to Bethel, Lisola and Halifax, said that the opposition to France was inevitable because France was too powerful. Although William did not explicitly mention the balance of power, Wout Troost showed that his concern for the 'liberty of Europe' could be understood as following 'a balance-of-power policy avant la lettre.' 72 The war ended in the autumn of 1697 with another series of treaties called the Peace of Ryswick. 73 Once again, status quo ante (bellum) was key in the treaties with its representative verb to restore in various forms.

The War of the Spanish Succession and the Peace of Utrecht
The War of the Spanish Succession was another conflict fought to preserve the balance of power in Europe. Louis XIV (Figure 3) attempted to put his grandson on the Spanish throne as the childless Charles II wrote in his will. This potential succession provoked the (second) Grand Alliance convened in 1701 between William III, the States General, the Habsburgs and several other (German) states. The rationale was that the King of France could potentially become so powerful that Europe would be in imminent danger of losing its liberty due to the threat of universal monarchy. This was the official casus belli which the allied states employed against the explicit will of the deceased king.
The number of pamphlets concerned with the French universalist goals and the balance of Europe tied to the Spanish Succession was unprecedented. In this regard, the Habsburg side lagged behind the English. 74 Even before the war declaration, William III addressed the House of Commons in 1701 to support his actions 'if you do in good earnest desire to see England hold the balance of Europe' as 'England ought to take in the preservation of the liberty of Europe.' 75 This struggle came into the broader 'everyday' public sphere, i.e. not just pamphlets but also newspapers. London Gazette published several speeches addressed to the king supporting his policies and the 'Balance of the Power of Europe.' 76 In another issue they praised the king's 'Glorious Design of Re-establishing a just Ballance of Power in Europe.' 77 A lot of diplomatic correspondence confirmed the contention that preventive war to limit the growth of neighbouring power was a just casus belli and statesmen made declaratory statements with such goals. In May 1702, Queen Anne, the sister-in-law of the just deceased William III (died in March 1702), officially declared war to Louis XIV and Philip V of Spain, who had been acknowledged as [Bourbon] King of Spain by England before. England published the declaration which qualified the war as a response to the 'French taking' of the Spanish Crown and 'for preserving the Liberty and Balance of Europe, and for Reducing the Exorbitant Power of France.' 78 The war also had other reasons, like 'Asiento de Negros,' the French support of the Catholic succession in England, the French acts in the Netherlands, etc.
Countries did not follow only anti-hegemonic policies, as many opponents highlighted at the time. The peace and balance in Europe were key for the English trade and commercial interests. Charles Davenant from the Whig opposition wrote an essay about the balance of power as propaganda for the war against France. England, according to him, should play the role of the balancer, which should not just follow the interest of England but the 'interest of Europe.' 79 He defended the 'traditional' role of England as the balancer by claiming that 'for many years we have pretended to hold the balance of Europe, and the body of the people will neither think it consistent with our honour nor our safety to quit that post.' 80 Daniel Defoe was hired as a propagandist by Robert Harley to support England's involvement in the war, although he had previously opposed it. In 1704, Defoe anonymously started publishing the weekly newspaper A Review of the Affairs of France: and of all Europe, 81 which covered the War of the Spanish Succession. Defoe defended the constant vigilance as there can be no permanent allies or permanent enemies in accordance with the nature of the balance. Defoe always asked himself the question 'WHAT'S NEXT?' 'Every Power, which over balances the rest, makes itself a Nuisance to its Neighbours. Europe being divided into a great Variety of separate Governments and Constitutions; the Safety of the whole consists in a due Distribution of Power, so shared to every Part or Branch of Government, that no one may be able to oppress and destroy the rest.' 82 At the time, the regional disputes or affairs quickly became international and European problems. During the War of the Spanish Succession, the Hungarian War of Independence  under Ferenc II Rákóczi broke out. Rákóczi was a nominal ally of France and part of the imperial army had to return to Hungary to quell the rebellion. The key thing to understand is that these conflicts in Hungary and Transylvania were not isolated, limited or local affairs, but they were always seen in a broader context. In his memoirs and political texts, Rákóczi often thought of the balance-of-power politics. In connection to the war in Spain, he stated that 'whether the French or the Habsburgs will win this present war, the European balance of power will be upset.' 83 This dynamic nature of the balance-of-power discussions became a commonplace in the long seventeenth century. During the war, out of pragmatic concerns, a major shift in the balance-of-power discussions occurred. 84 When Emperor Joseph I died without an heir in 1711, his younger brother Charles VI, who was supposed to acquire the Spanish throne, succeeded him on the imperial throne. Thus, the allies realised that with the victory they could be putting the Austrian emperor on the Spanish throne which would not be much better than the united French-Spanish crown. The Austrians or the Habsburgs as a potential threat to the European balance rearranged policy priorities and public discourse.
In late 1711, Jonathan Swift wanted to present the strong case for concluding a separate peace treaty with France; foreign secretary Bolingbroke helped drafting the text. Swift warned that 'to have the Empire and Spanish Monarchy united in the same Person, is a dreadful Consideration, and directly opposite to that wise Principle, on which the Eighth Article of the Grand Alliance is founded.' 85 Eighth article dealt with the balance of power and the threat of the concentration of too much power. Ironically, it also warned against concluding separate peace. 86 After they had been fed war propaganda for ten years, Swift's book was key in convincing the English public for the Congress of Utrecht in 1712.
The first explicit reference to the balance of power in the major international treaty was in the Treaty of Utrecht in 1713. 87 In the renunciation of the King of Spain to the French throne, which was included in article X of the Treaty between France and Great Britain, the King of Spain stated that 'to attain general peace, [is] to ensure forever the universal good and rest for Europe, and to establish an equilibrium between the powers.' 88 The goal of Utrecht was 'to settle and establish the Peace and Tranquility of Christendom by an equal Balance of Power (which is the best and most solid Foundation of a mutual Friendship, and of a Concord which will be lasting on all sides).' 89 The Treaty of Utrecht brought a new system of balance of power in Europe and to the eighteenth century. 90 The balance of power was now fully legitimised as a legal principle informing the inter-state politics.

Conclusion
The ambiguity and flexibility of the balance-of-power idea has been one of the reasons for its survival to this day. In the long seventeenth century, the balance-of-power idea often acted in opposition to the idea of universal monarchy wanting to secure hegemony abroad and harmony at home. Simultaneously with the spread of the balance-of-power principle, the public sphere was forming. Printing allowed the ideas to spread quickly and widely. The international treaties were translated and published in pamphlet forms in several editions in many states. Numerous pamphlets discussed current political affairs in detail, so the principle was not just used by historians or jurists in abstract texts anymore but also by, often anonymous, political 'pundits.' The balance of power was part of the anti-hegemonic argumentation which argued for peace in the European order although it was often used as an excuse for war. The principle of balance was present in international treaties: implicitly in Westphalia and explicitly in Utrecht. Westphalia has often been considered as the dawn of the balance-of-power system but, in this sense, it was mostly restricted to the religious balance in the Empire. Thus, it was only one of several stepping stones in the seventeenth century towards cementing the central status of the balance of power in the eighteenth century. I argued that the balancing was subject to numerical assessment which is manifested in interactive alliance treaties trying to reach just reciprocal responsibilities.
Between the two great treaties, the balance-of-power idea came out of the diplomatic background and into the diplomatic foreground. The dynamic and interactive nature of the balance forced the statesmen to consider and evaluate the reciprocal responsibilities. It should be noted that international law made significant progress during this time and that it gradually moved away from its origins and emancipated itself from natural law. In essence, the principle of balance of power shifted from the tradition of natural law to the tradition of positive law. Balance and its manifestation in Libra have always been associated with Justice, so its presence in law is no surprise. The balance of power became the central concept for the stability and peace in the inter-state system of Europe in the eighteenth century.