This chapter provides a history of the idea of custom both in definitions and as presented in texts about lay legal life before the coutumiers. The first part of the chapter examines the struggle to define custom from late antiquity to the time of the coutumiers. It shows that thinking about and defining custom in its legal capacity was no obvious thing: while there where common definitional elements, the quest to define custom was marked by debate and a lack of consensus that would continue into the fourteenth century.

The eighth and final chapter examines the larger effects of textualization and vernacularization. The combination of the new technology of writing with the social choice of the vernacular permitted ideas about custom to circulate beyond their traditional local community ambit. Previously rooted laws and customs grew legs, and customary legal ideas could be transmitted though the circulation of texts and shared outside their local setting. In fact, this is when we start seeing the term ‘common law’ appear in French texts, a term scholars associate in this period with either royal law in England or with Roman and canon law as law that was common to Europe. This French ‘common law’ has been hotly debated. This chapter contributes to this debate by using the coutumiers to show how a French ‘common law,’ in the sense of a pool of common customary legal knowledge, was developing in France. This, in turn, implies more similarity between the legal cultures of France and England in this period than previously thought.

This chapter argues that the French coutumiers are part of a Europe-wide vernacular legal revolution. Traditional narratives set these texts within the transition from custom to law, or as attempts to make custom more elegant in the face of a sense of inferiority to Roman law. The question of language of these early written customs has received little attention since outdated debates between Romanists and Germanists over whether custom originated in primordial Germanic tribes or was a disguised spin-off of university legal studies. However, language was key to the development of a written customary law. Vernacular writing in Europe began in earnest in the later twelfth century and proliferated afterwards. Coutumier authors chose to ride this wave of vernacular writing, rejecting the language of the universities and traditional written record in favour of the language of new histories, epics, and romance. The coutumiers were part of the new vernacular culture; it was a literature of lordship and dispute resolution in the lay courts for a lay public who lived in the vernacular.

The main question scholars have asked about the coutumiers is the extent of ‘penetration‘ or ‘influence‘ of Roman law on customary law. That there was influence is an undeniable fact. While the history of the coutumiers is undoubtedly connected to and overlaps with Roman law, this chapter challenges current historiography, which places Roman law at the centre of the development of written custom. Instead of asking how well an author knew his Roman law or how much of it was used in each text, this chapter looks more widely at citation practices, to establish what authorities were used and with what reverence they were treated. The citation practices in the coutumiers betray their authors’ confidence vis-à-vis the more august Roman law. These authors used learned law in service of their own projects but did not feel bound by its authority – unlike university thinking that famously placed Roman law in the middle of the page and medieval commentary in the marginalia. Roman law was certainly an important source for some coutumiers, but rather than treat it reverentially as an authority their authors used Roman law to build something new, lay, customary, and vernacular.

The sixth chapter examines the relationship between coutumiers as texts that describe custom, and custom in practice. The difficulty with discussing this is that the coutumiers only begin to be cited in court records at the very end of the thirteenth century and very rarely even then. This was not unusual for the lay courts of northern France in this period, which cited ‘custom’ and not lawbooks or specific precedents. I discuss the relationship between the coutumiers and representations of practice – as filtered through its documentary record-keeping – in two ways. On one level, this chapter shows how at least some people were thinking about court cases that they presided over, took part in, witnessed or heard about. On another, this chapter demonstrates how the coutumier represents practice differently from other remaining records and how coutumier authors used what they saw in practice to extract principles and articulate general rules. Through the coutumiers, we can see how individual actors reshaped specific cases and transactions into general principles, and those general principles into a body of customary law.

The fourth chapter discusses the question of why now – why did customary law become the subject of vigorous written output at this particular thirteenth-century moment? The answer lies in the politics of customary law or, more specifically, the changes in both society and legal culture that created new zones of competition between secular and ecclesiastical courts. Competition between the temporal and spiritual jurisdictions was, of course, not new. The investiture controversy that began in the eleventh century, based in the conflict over the right of appointment of church officials, showed this to be a key issue of the high medieval period. The nature of competition manifested in the coutumiers was a little different. The coutumiers aimed to theorize, regularize, and professionalize the secular courts in the face of ecclesiastical courts, which had already gone through the same process and offered a competing forum at a time when boundaries were still being defined.

This book tells the story of the formation of a new field of knowledge. It shows how various authors combined their knowledge, experience, and critical thought to write lawbooks that made various disparate customs into a field of knowledge known as customary law. These authors wrote texts, known as the coutumiers in the French legal tradition, in thirteenth-century northern France. ‘Customary law’ typically refers to a type of rule made in practice, and in the courts, by the community, which can include ‘the people’ in some form, lords and kings, or lawyers and judges. Customs concerning specific rules of property, succession, and other subjects certainly emerged out of this oral practice. Coutumier authors, however, successfully crafted customary law into an expository genre of writing, one that took ideas of custom from practical experience and different forms of book learning and transformed them into bodies of customary law.

Unwritten law, or ius non scriptum, was a prominent definition of custom in the later medieval period developed especially in learned circles. Though ‘written custom’ should be a contradiction, this was unevenly perceived. Unlike the authors of the Glanvill and Bracton lawbooks in England, the coutumier authors did not seek to understand or legitimate their writing of custom within this learned framework. Those coutumier authors who addressed the question of writenness viewed the idea of ‘written custom’ as unproblematic. Instead, they saw writtenness and its lack through a practical lens, as an aspect of custom’s potential to be retained in memory. This does not mean they viewed written custom as ‘fixed’. Writing in a time of fundamental legal change, they understood that even the custom expressed in written text was mutable. While writing custom could help to keep it memory, it was potentially changeable in future versions of the text.

The thirteenth-century coutumiers capture a moment of intellectual ebullience. They were part of the formative moments of the lay courts and the theorization of ‘law in practice’ and in this sense the coutumiers were the linchpin of French legal thinking until the Revolution – and beyond in some French colonies. They created something powerful in the French legal imagination, so powerful that their use only increased with time and eventually became official law when the kings demanded coutumiers to be written for all the regions of France in the fifteenth and sixteenth centuries. This was all due to the ingenuity and intellectual creativity of the thirteenth-century lay jurists who borrowed, constructed, and effectively created a field of knowledge known as ‘customary law’.

This chapter explores how writing affected the nature of custom itself. The writing of custom did not fix or petrify custom and end its malleability or creativity, as scholars have assumed. Drawing on the work of literary scholars on the nature of medieval vernacular text and manuscript culture, I argue instead that each manuscript provided one authoritative version of custom and constituted one voice in a conversation over custom that continued with written text. This conversation can be seen where differences between manuscripts show diverging opinions about proper custom. This, in turn, meant that custom remained creative and dynamic even in written form. The purpose of the coutumiers was not to copy practised custom and faithfully record it with perfect accuracy in text. Rather, the coutumiers were meant to change the patterns of thought of ‘those who would hear or read the text’ and show them how to think in a legal manner, like a lawyer, judge, or sophisticated litigant. Teaching modes of thought rather than rules permitted those who did not spend years in university to understand the framework and rhetoric of lay courts, and enabled them to navigate these through changing rules, time, and circumstance.