“Masterpiece” is a notoriously overused term in book reviews. However, if it be taken to imply the exploration of a field of inquiry into which the writer has unique insight that transcends everything that has previously been written on a particular subject, and that not only sets an entirely new standard but establishes criteria that are likely to prove definitive for future research, then Pierre Chaplais's book is indeed a masterpiece. Here, limpidly and concisely set out, are the fruits of half a century's exploration of the diplomatic archives not only of England but of a dozen or more European states. Conceived as the first part of a commentary on the three volumes of texts and facsimiles that Chaplais published between 1975 and 1982, under the title “English Medieval Diplomatic Practice,” the remit of Chaplais's new book might appear a narrow one, being limited to two principal themes: the forms and classification of diplomatic correspondence and the constitution of diplomatic missions. Yet within these confines, Chaplais achieves for medieval diplomacy what Felix Liebermann and Frederic Maitland long ago achieved for medieval English law and what Léopold Delisle and Arthur Giry attempted to achieve for medieval diplomatique: the establishment of a coherent system of rules whose application extends far beyond the circumstances of any particular time or place. The wealth of the detail is as remarkable as the depth of the author's insight. Thus, in the course of a mere ten pages, devoted to the title, address, and language used in diplomatic correspondence, Chaplais delivers one gemlike dictum after another: that chanceries tended, in their response to particular letters, merely to copy the titles used in incoming correspondence; that any departure from this rule is likely to denote diplomatic tensions; that an address to a fellow ruler as “dominus” or the adoption the title “fidelis” by the sender of a letter implies feudal relations of overlordship or subjection; and that, to descend from the general to the particular, in their search for politeness in difficult circumstances, by the 1430s, French negotiators preferred that their king be styled “our adversary” by the English rather than that he be addressed by what was regarded as the far more humiliating style “Karolus de Valoys.” Amid all this, and apart from revealing the riches of the dictaminal treatise of Master Geoffrey de Everley, Chaplais still finds time to present his readers with a definitive treatment of the cursus. Here, as throughout, Chaplais's rules command respect, not only because of the depth of his evidential enquiry, but because he prefers to follow the typology imposed by medieval writers rather than to devise some more rigid system of his own. His discussion of sealing methods and the classification of letters patent and close, for example, is far in advance of anything produced by the Conseil International des Archives, precisely because it is so firmly rooted in medieval practice rather than postmedieval theorizing. “The French think too much,” remarked the seneschal of Gascony in a letter to Edward II (80). Whether or not this is a statement that should be applied to the Conseil International des Archives, the thoughts of Chaplais are invariably informed with common sense and are set out with a clarity that is perhaps more Gascon than French.

All medievalists, not merely those engaged in the study of diplomacy, will benefit from this book. For those interested in literacy, we have here evidence of the dismal Latinity of England's kings as well a host of particular instances: of Edward III signing letters to the pope, for example, and of the arrangement whereby any such letters with the invocation “pater sancte” were to be taken as emanating directly from the king. For those interested in language, there is a wealth of information here on the relative fortunes of Latin and French, while for anyone who has ever grappled with the intricacies of dating styles, there are delightful if cautionary tales of the deliberate backdating or misdating of letters. Likewise, on the speed of travel and communication, the rituals of greeting, the dangers of entrusting messages to forgetful or overinventive envoys, and the entire question of memory versus written record, Chaplais serves up a banquet of fresh delights.

There are only two regrets. The first is that, in supplying a commentary to surviving diplomatic texts, Chaplais prefers to bypass at least some of the evidence from chronicle sources. This is particularly true of the period before 1200: a period for which, across Europe not merely in England, we have few diplomatic letters or treaties but a wealth of anecdotal evidence from the chroniclers on how, where, and in what circumstances diplomatic exchanges took place. The other regret, all too rare these days, is that the book is too short. This is merely the first of what was clearly intended to be a two-volume study. The second volume hovers in the background to various of Chaplais remarks, and on page 222 even finds its way into the footnotes, in which we are referred to an as yet entirely spectral chapter 4. Chapters 4 and 5 were to have dealt with treaty making and diplomatic “law” and would, no doubt, have deployed precisely the sort of anecdotal evidence from the chroniclers that is bypassed in chapters 1–3. One suspects that these missing chapters are already written. They formed the basis of various of the lectures that Chaplais gave at Oxford and hence supplied whatever understanding of medieval diplomatic can be claimed by an entire generation of Oxford graduates. If these chapters do indeed lurk in some attic or box file, then the publisher who can be persuaded to unearth them will render almost as great a service to medieval studies as has been rendered here by Chaplais himself.