By: Randall Lesaffer
Students of diplomatic and international legal history will undoubtedly be familiar with the painting by the Dutchman Gerard ter Borch (1617–81) of the Peace of Münster. It catches the moment wherein the Dutch delegates take the oath on the peace treaty with Spain, just after the Spanish delegates had finished theirs. On the table, in front of the Spanish ambassador, Gaspar de Bracamonte, Count of Peñaranda (1595–1676), lies the book of the Holy Gospels, with a cross on top of it. The count’s right hand, who according to custom and treaty touched these objects during the swearing of the oath, is still resting on its pages. In his left hand, he holds the text of the formula. His Dutch counterpart also holds a paper with the text, while he sticks up two fingers of his right hand, just as his six colleagues do.
The ceremony took place in a formal room, known today as the Hall of Peace, in the town hall of Münster on 15 May 1648. It marked the one but ultimate step, before publication, in the procedure of finalizing the peace treaty between Spain and the Dutch Republic (1 CTS 1). The definite text of the treaty had been signed by the delegates earlier that year, on 30 January. Afterwards, it had been ratified by the principals, the Spanish King Philip IV (r 1621–65) and the Estates-General of the Republic, without, however, the approbation and accession by the province of Zeeland. The ceremony in May concerned the formal exchange of the ratification documents. The swearing of an oath by the delegates themselves was a fairly rare addition.
If the oath-taking by the delegates on the occasion of the exchange of ratifications documents was particular, the taking of an oath by the principals had been a crucial part of the procedure of treaty-making since the Middle Ages. During the twelfth and thirteenth centuries, a standardized procedure for the negotiating and making of treaties between princes and rulers emerged in Christian Europe. Under this procedure, which the German scholar Ludwig Bittner called the ‘zusammengesetzte Vetragsschliessungsverfahren’ (the composite procedure for the making of treaties), three consecutive sets of formal documents were made. Firstly, the principals—princes and ruling bodies—of the polities involved in the negotiating process appointed and mandated delegates to negotiate the treaty. These mandates—full powers—were signed and stamped with the official seal of the principal. Secondly, at the end of the negotiations, the delegates would fix the text of the treaty under their signatures. On occasion, they would take an oath, promising that their principals would accept and ratify the text. Thirdly, the principals ratified the treaty text, which was then formally presented to or exchanged with the treaty partner.
The third phase traditionally involved a double action: the signing and sealing of ratification documents to be presented to the opposing party, and the taking of an oath. Until the late seventeenth century, the final clauses in important treaties, such as peace treaties, generally stipulated in fine detail the manner in which the ratification of the treaty would take place.
The string of Franco-Spanish peace treaties which ran from the early sixteenth century to the end of the seventeenth century contained a ratification clause, which was copied from one treaty to another. In the English version of the Peace of Nijmegen of 17 September 1678 (14 CTS 441), the plenipotentiaries promised that the treaty would ‘be ratify’d purely and simply, without adding anything’ and that the two kings would ‘furnish the Ratifications with authentick and seal’d Letters’ within six weeks. After the letters were made and transferred to the opposing side or his delegate, the two kings would then, ‘in the presence of such Person and Persons as it shall please’ the other king to depute for this, ‘swear on the Cross, Gospel, Canons of the Mass, and on his Honour, to observe fully, really and faithfully to accomplish all the Articles’.
The clause exemplified what constituted standard procedure between the Late Middle Ages and the seventeenth century, at least among Catholic powers. Oaths were taken in the form of a religious ceremony. As they involved the invocation of God, they were commonly taken in church and were accompanied by gestures such as the touching of the Cross, the Gospels, the canons of the mass and/or holy relics. The ceremony could also be attested for in a special signed and sealed document, or a report of it was included in the ratification document. This was a viable alternative to having the oath witnessed by a mandated delegate of the opposing side.
The double ratification of the treaty through signed and sealed documents, on the one hand, and by an oath, on the other hand, was a practice which dated back to the Late Middle Ages. Regardless of the fact that the two actions could be attested by the same document, they were separate constitutive acts that each by itself would have made the treaty binding upon the principals. Whereas the signing and sealing made the treaty binding under general principles of contract under natural law and jus gentium—in its meaning of common, universal institutions of law, Roman law, canon law, feudal law and many domestic or local laws, the oath gave it additional validity and, above all, enforceability before ecclesiastical courts. As perjury was a grievous sin, it fell within the jurisdiction of the ecclesiastical courts and was sanctionable by the most severe ecclesiastical sanctions, including excommunication. Under standard canon law doctrine, the jurisdiction of the church extended into the external forum, if it was necessary for the Church to intervene in secular disputes in order to perform its spiritual tasks of preserving a sinner’s eternal soul in the internal forum.
In the decades before the Reformation caused the collapse of the religious unity of Christian Europe in the early sixteenth century, ratification clauses commonly included an express invocation of papal jurisdiction for disputes about the observance and violation of the treaty. Treaty parties frequently promised not to request any papal dispensations or even submitted themselves a priori to automatic ecclesiastical sanctions—excommunication—in case of breach of the treaty. Such express submissions to ecclesiastical jurisdiction were unnecessary, as under the papal decree Ille Novit (1204), the Church had arrogated itself the right of jurisdiction over treaties confirmed by oath. Their practical purpose was that they spelt an agreement between the parties to bring disputes before the papal court, rather than any other ecclesiastical court.
The religious division of Christian Europe, with the rejection of papal authority by its Protestant part, brought an end to these express references to papal jurisdiction and sanctions. By the second half of the sixteenth century, such references had completely disappeared from treaties, even among Catholic powers. The ratification clauses were thus devoid of any express submission to ecclesiastical courts, but they retained the provision of taking an oath as a ritual, religious action. As the ceremony at Münster shows, this entailed different ritual gestures for Catholics or Protestants.
Over the seventeenth century, ratification by oath gradually fell into disuse, first in treaties involving Protestant powers but later also in treaties among Catholics. As ecclesiastical courts had stopped playing a role in the management of disputes over treaties, oaths had lost their main practical value. By the turn of the eighteenth century, they had as good as completely disappeared from treaty practice, leaving the written ratification as the sole form of ratification. The Franco-English Peace Treaty of Utrecht of 11 April 1713 offers a good example of a standardized clause. The only matter for choice that was left for the parties now was the place where and the term wherein ratification documents had to be exchanged.
Lastly, the solemn ratifications of this present agreement and alliance, made in due form, shall be delivered on both sides, and mutually and duly exchanged at the royal pace of Ryswicke, in the province of Holland, within the space of three weeks, to be reckoned from the day of the subscription, or sooner, if it may be (Art. 17, 21 CTS 409).
Jenny Benham, Peacemaking in the Middle Ages. Principles and Practice (Manchester and New York: Manchester University Press 2011).
Ludwig Bittner, Die Lehre von den völkerrechtlichen Vertragsurkunden (Berlin and Leipzig: Deutsche Verlags-Anstalt Stuttgart 1924).
Allen Z. Hertz, ‘Medieval treaty obligation’, Connecticut Journal of International Law, 6 (1991) 425-43.
Randall Lesaffer, ‘From Lodi to Westphalia’ in Randall Lesaffer (ed.), Peace Treaties and International Law in European History. From the End of the Middle Ages to World War One (Cambridge: Cambridge University Press 2004) 9-44.
Walter Ullmann, ‘The medieval papal court as an international tribunal’, Virginia Journal of International Law, 11 (1970-1) 356-73.