International Judicial Monitor
Published by the International Judicial Academy, Washington, D.C., with assistance from the
American Society of International Law

Winter 2013 Issue

Historic Moments in International Law


The Art of Treaty Repudiation – Medieval Style

Stephen C. NeffBy: Stephen C. Neff, Reader in Law, University of Edinburgh Law School

King Charles V of France, who reigned from 1364 to 1380, was given the sobriquet of “the Wise.”  This is partly on the basis of a massive book collection which eventually constituted the core of the National Library of France.  But in 1368, his sagacity was directed towards a real-world conundrum of international law.  He was seeking a lawful means of repudiating the Treaty of Brétigny, which his father John II had concluded in 1360 with the English king Edward III, and which had brought a halt to hostilities between the two countries.  The treaty had been signed in the wake of the stunning English victories at the Battles of Crécy (1346) and Poitiers (1356), in the conflict that would retrospectively be dubbed the Hundred Years’ War.  According to the treaty, there was to be a mutual renunciation of rights by the two rulers – with Edward renouncing his claim to the French throne, and John correspondingly renouncing his claim to sovereignty over the Duchy of Aquitaine.  John’s renunciation would leave Edward as the absolute sovereign of Aquitaine rather than (as previously) as mere a fief-holder under the French crown.

Charles was determined to resume the hostilities in order to avenge the humiliations suffered by his country.  But he needed – or at least assumed that he needed – a credible legal basis for repudiating the Treaty of Brétigny.  Two points are of interest here.  First, there appears to have been no doubt that Charles was bound by the Treaty, even though it had been concluded by his father – i.e., that the Treaty effectively bound France as a state, and not just the ruler concluding it as a person.  Second, it also appears to have been taken for granted that there was no right on the part of a treaty party to terminate an agreement at will.  That is to say, there was a clear acceptance that the rule of law (“pacta sunt servanda”) stood above the whims of sovereigns. It was accordingly necessary for Charles to unearth some just cause for the repudiation that he sought.  The most obvious possibility was to find a breach of the treaty by the English.

Charles trod carefully. He found the legal opening that he sought when the English government began levying taxes in the Armagnac area of Aquitaine.  Two local French notables contended that the taxation was illegal, as an infringement of their local customary rights.  Charles supported these disgruntled lords.  But he took care not to rely too heavily on his own views of the case.  He dutifully set about obtaining legal opinions on the matter from eminent jurists at the Universities of Bologna, Montpellier, Toulouse, and Orléans.

Armed with this juridical ammunition, Charles convened a council in Paris, which duly concurred in his support for the Armagnac lords.  The king then issued a summons to the Black Prince (Edward III’s son) in December 1368, ordering him to answer the charges against him by May of the following year.  Edward III became angry at this action, which constituted an exercise of sovereign rights over Aquitaine on Charles’s part, contrary to the peace arrangements.  He retaliated against Charles by resuming his claim to the French throne. On 2 May 1369, the Black Prince’s name was solemnly called out in the Paris parlement (i.e., court) – to no avail. A council was then held, which concluded (not surprisingly) that England was in breach of the Treaty of Brétigny and that its unlawful conduct had forced a resumption of hostilities onto Charles V.


The English were not be outdone in this legal duel. Three weeks later, a similar ceremony took place at the Palace of Westminster in London, at the opening of a session of the English parliament, where France was accused of violating the peace arrangements.  Presenting the case against France was the chancellor William of Wyckham (founder of the famous public school of Winchester and also of New College, Oxford).  On this occasion, too, the outcome produced no surprises.  It was agreed that King Edward III was justified in reasserting his claim to the French throne. The following month, the king duly altered his official seals, to add the arms of France to them.

Later that same year, in November 1369, Charles V declared the Black Prince to be a disloyal vassal and announced the confiscation of the Duchy of Aquitaine as a penalty.  He also announced that, as of May of that year (i.e., the time of the Black Prince’s failure to respond to the summons), the two countries were once again at war.  Charles’s goal had been attained.

A couple of things are striking about this story.  The first is its demonstration of an intensely legalistic mentality that prevailed in the Middle Ages. Both rulers in the quarrel took scrupulous care to give at least the appearance of a formal legal proceeding before pronouncing his enemy to be a lawbreaker.  A second interesting point is that the law in question – governing termination of treaties – was essentially identical to that which prevails today, instantiated in the Vienna Convention on the Law of Treaties. The “medieval style” of treaty termination may have been more dramatic than that of the present day in terms of procedure and ceremony and the like.  But the substantive law underlying it was the same.

For a more detailed account of these proceedings and the many legal issues involved, readers may profitably consult volume 2 of The Hundred Years’ War (1999) by Jonathan Sumption.  He brings an acute legal mind to bear on the story, as he now serves as a judge on the British Supreme Court.

Incidentally, the renewed hostilities went reasonably well for Charles.  He succeeded in recovering most of the losses suffered previously, gradually driving the English from all of France except for Calais and the Duchy of Aquitaine.  The next respite in the struggle did not come until 1396, after Charles’s death, with the marriage of his successor’s daughter (aged six) to King Richard II of England (then a venerable twenty-nine).  Clearly, the law regarding marriage capacity has undergone changes since the 14th century, even if the law of treaty termination has not.

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© 2013 – The International Judicial Academy
with assistance from the American Society of International Law.

Editor: James G. Apple.
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