This is a thread that Jean-François Nieus has been pursuing for some twenty years, as part of research into the uses of writing, which elevates documents to objects of history in their own right. This approach, developed over several decades, sheds light on medieval society in all its dimensions: cultural, of course, but also social, political, economic, and religious. "Writing was rare in the early Middle Ages. It gradually gained importance in social practices, with a clear shift in the 12th and ^13th centuries—i.e., during the High Middle Ages—when people began to write much more and diversify the formats and functions of writing," he explains. 

Jean-François Nieus is particularly interested in documentary productions associated with the exercise of princely power and seigneurial management, within an area stretching from the Anglo-Norman world to the Southern Netherlands. Princely and noble archives are essential for understanding the relationships of domination in the so-called "feudal" age, that of territorial principalities and seigneurial lordship, but also issues of family identity and lineage, which were central concerns of the aristocracy. "After the mid^-12th century, most noble families began to keep archives, initially consisting of a few received charters, but soon enriched with their own administrative productions. Although the majority of these secular collections have now disappeared, there is evidence of their existence," he explains. The vicissitudes of the history of the great families and the French Revolution contributed to the loss of these fragile documents, so that today only a handful of archives from ^the 12th and 1^3th centuries remain.

Those studied by Jean-François Nieus nevertheless cover a wide range of types: they include "chartriers" (collections of original charters), "cartulaires" (collections of copies of charters), "formulaires " (collections of model charters and letters), "censiers" (descriptions of the property and income belonging to a seigneury), lists of vassals and fiefs, accounts, etc.

Jean-François Nieus also carries out critical editing work. He will soon publish the archives of the Béthune family (now Pas-de-Calais), as well as those of a small abbey linked to these lords, Saint-Jean-Baptiste de Chocques, whose collection, destroyed during the French Revolution, he is reconstructing.

This patient and meticulous work of discovery, deciphering, studying, and publishing sources that are sometimes very scattered helps to restore the memory of an era and enrich the documentation available to researchers.

In addition to administrative writings, Jean-François Nieus is also passionate about an auxiliary science of history: "sigillography," the study of seals. These small wax discs attached to official documents provide a unique window into the cultural representations of the time. In particular, they show how, after 1066, under the influence of William the Conqueror, a new image emerged: that of a knight on his galloping horse, weapon in hand. This motif, which was completely new at the time, quickly spread among princes and nobles, becoming a powerful symbol of chivalry.

Following this evolution, Jean-François Nieus also traces the spread of coats of arms—heraldry—which he sees emerging in the early ^12th century in northern France and the Anglo-Norman region. Equestrian seals, heraldic signs, and chivalric rites such as tournaments thus formed a cultural community that invented and asserted itself in this area.

If the Middle Ages fascinate Jean-François Nieus so much, it is undoubtedly because of their strangeness: a world very distant from our own, often distorted by stereotypes. "It's a difficult period to popularize because it's so different from our own, even though, in reality, we owe it a great deal. What's more, perceptions of it are marred by numerous clichés, and the general public still views it very negatively, as reflected in everyday language by the sinister adjective 'medieval,'" observes the researcher.

What are the reasons for this negative view? The perspective of intellectuals in subsequent eras, who saw it as the origin of all the archaisms they wanted to combat. Nineteenth-century historians, who gave the discipline its scientific foundation, also passed on erroneous interpretations, which contemporary research is gradually correcting. 

Jean-François Nieus appeared in episode 1 of season 3 of the documentary series "Batailles de légende" (Legendary Battles), which focused on the great battle of Bouvines between King Philip II Augustus of France and a coalition led by King John of England (1214).

To understand how the transition to Christianity came about, researchers generally turn to the great authors, and in particular Saint Augustine, the key figure of Christian antiquity whose writings have been preserved the most. Alongside his best-known works (such as The City of God or The Confessions), Saint Augustine is also the author of short treatises on practices such as marriage or baptism. "In my early post-doctoral research, I sought to understand how these short texts by Augustine, and other North African sources, circulated in the West between late antiquity and the early Middle Ages. This was a period of religious mixing when the first Christian communities were setting up systems of initiation and teaching", explains Matthieu Pignot.

Very quickly, the researcher's interest also turned to anonymous or pseudepigraphic texts (erroneously attributed to a known author), which had fallen into oblivion in favor of writings by authors, and which also addressed these questions of religious education. "This is the starting point for my research project. These texts are difficult to study because, circulating under several names, we don't know their true author. We don't know who wrote them, and we know little about their ancient and medieval transmission. It is precisely these grey areas that make them so interesting", continues the historian.

To address this question, Matthieu Pignot starts from two bodies of texts: on the one hand, a collection of 80 sermons wrongly attributed to Fulgence of Ruspe and, on the other, a Latin translation of an anonymous collection of Greek philosophical maxims by Rufinus of Aquileia (IV-V^th century), an author who played an important role in the transmission of Greek thought in late antiquity in the West.

The methodology favored by Matthieu Pignot for this research involves the use of digital publishing. The aim? "To bring into existence and enhance the value of these texts, which don't have the privilege of having an author's name, and some of which haven't even been printed. What's more, stylistic and linguistic analysis tools will perhaps make it possible to provide clues about the author, or at least to group texts together, based on recurring writing tics."

With this project, Matthieu Pignot also aims to develop the automated manuscript transcription component, which is still under development. "My aim is to contribute to the improvement of these tools through my own transcriptions and to participate in the dynamic of interest in medieval manuscripts in archives and libraries", concludes the researcher.

Matthieu Pignot is a member of the research center PraME("Pratiques médiévales de l'écrit"), part of the research institute PaTHs ("Patrimoines, Transmissions, Héritages"). He also collaborates with the Institut d'études augustiniennes (Paris) and the University of Nijmegen.

I was fascinated by the research field of one of my professors, Guy Demortier. He was working on the characterization of antique jewelry. He had found a way to differentiate by PIXE (Proton Induced X-ray Emission) analysis between antique and modern brazes that contained Cadmium, the presence of this element in antique jewelry being controversial at the time. He was interested in ancient soldering methods in general, and the granulation technique in particular. He studied them at the Laboratoire d'Analyses par Réaction Nucléaires (LARN). Brazing is an assembly operation involving the fusion of a filler metal (e.g. copper- or silver-based) without melting the base metal. This phenomenon allows a liquid metal to penetrate first by capillary action and then by diffusion at the interface of the metals to be joined, making the junction permanent after solidification. Among the jewels of antiquity, we find brazes made with incredible precision, the ancient techniques are fascinating.

In fact, this was one of Namur's fields of research at the time: heritage sciences. Professor Demortier was conducting studies on a variety of jewels, but those made by the Etruscans using the so-called granulation technique, which first appeared in Eturia in the 8th century BC, are particularly incredible. It consists of depositing hundreds of tiny gold granules, up to two-tenths of a millimeter in diameter, on the surface to be decorated, and then soldering them onto the jewel without altering its fineness. So I also trained in brazing techniques and physical metallurgy.

I applied for a position as a physicist at CERN in the field of vacuum and thin films, but was invited for the position of head of the vacuum brazing department. This department is very important for CERN as it studies methods for assembling particularly delicate and precise parts for accelerators. It also manufactures prototypes and often one-off parts. Broadly speaking, vacuum brazing is the same technique as the one we study at Namur, except that it is carried out in a vacuum chamber. This means no oxidation, perfect wetting of the brazing alloys on the parts to be assembled, and very precise temperature control to obtain very precise assemblies (we're talking microns!). I'd never heard of vacuum brazing, but my experience of Etruscan brazing, metallurgy and my background in applied physics as taught at Namur were of particular interest to the selection committee. They hired me right away!

CERN is primarily known for hosting particle accelerators, including the famous LHC (Large Hadron Collider), a 27 km circumference accelerator buried some 100 m underground, which accelerates particles to 99.9999991% of the speed of light! CERN's research focuses on technology and innovation in many fields: nuclear physics, cosmic rays and cloud formation, antimatter research, the search for rare phenomena (such as the Higgs boson) and a contribution to neutrino research. It is also the birthplace of the World Wide Web (WWW). There are also projects in healthcare, medicine and partnerships with industry.

For my part, in addition to developing vacuum brazing methods, a field in which I've worked for over 20 years, I've worked a lot in parallel for the CLOUD experiment. For over 10 years, and until recently, I was its Technical Coordinator. CLOUD is a small but fascinating experiment at CERN which studies cloud formation and uses a particle beam to reproduce atomic bombardment in the laboratory in the manner of galactic radiation in our atmosphere. Using an ultra-clean 26 m³ cloud chamber, precise gas injection systems, electric fields, UV light systems and multiple detectors, we reproduce and study the Earth's atmosphere to understand whether galactic rays can indeed influence climate. This experiment calls on various fields of applied physics, and my background at UNamur has helped me once again.

I was also responsible for CERN's MACHINA project -Movable Accelerator for Cultural Heritage In situ Non-destructive Analysis - carried out in collaboration with the Istituto Nazionale di Fisica Nucleare (INFN), Florence section - Italy. Together, we have created the first portable proton accelerator for in-situ, non-destructive analysis in heritage science. MACHINA is soon to be used at the OPD (Opificio delle Pietre Dure), one of the oldest and most prestigious art restoration centers, also in Florence. The accelerator is also destined to travel to other museums or restoration centers.

ELISA uses the same accelerator cavity as MACHINA. The public can observe a proton beam extracted just a few centimetres from their eyes. Demonstrations are organized to show various physical phenomena, such as light production in gases or beam deflection with dipoles or quadrupoles, for example. The PIXE analysis method is also presented. ELISA is also a high-performance accelerator that we use for research projects in the field of heritage and others such as thin films, which are used extensively at CERN. The special feature is that the scientists who come to work with us do so in front of the public!

I remember that in 1989, I finished typing my report for my IRSIA fellowship in the middle of the night, the day before the deadline. It had to be in by midnight the next day. There were very few computers back then, so I typed my report at the last minute on one of the secretaries' Macs. One false move and pow! all my data was gone - big panic! The next day, the secretary helped me restore my file, we printed out the document and I dropped it straight into the mailbox in Brussels, where I arrived after 11pm, in extremis, because at midnight, someone had come to close the mailbox. Fortunately, technology has come a long way since then...

The proximity between teaching and research inspires and questions. This enables graduate students to move into multiple areas of working life.

Come and study in Namur!

Serge Mathot (May 2025) - Interview by Karin Derochette

• The CERN accelerators complex
• The Science Portal, CERN's public education and communication center
• Newsroom - June 2025 | The Departement of physics hosts a delegation from CERN
• Newsroom and Omalius Alumni article - September 2022 | François Briard

In the photo: Édouard Lecanuet, production assistant at Histovery, Minister Valérie Lescrenier in charge of Tourism and Heritage, Marc de Villenfagne, managing director of the Citadelle of Dinant, and Axel Tixhon, professor in the History Department at UNamur, inaugurate the HistoPad, a 3D reconstruction tool of the history of the Citadelle of Dinant. A project scientifically validated by Axel Tixhon.

Thanks to an interactive tablet christened HistoPad, the public can explore the site like never before. At various points along the route, visitors discover historical scenes recreated in 3D, supported by rigorous documentation and faithful reproductions of period settings, costumes and objects.

Three key periods have been selected for this immersion:

• 1821, Dutch period and construction of the fort
• 1832, Belgian period during which the Citadelle becomes a military prison
• 1914, during the First World War, the site is the scene of confrontations

Professor Tixhon was involved in all stages of the project, as a member of the scientific committee. Initially, he highlighted historically interesting events and traces still visible today, such as artillery pieces, an old kitchen or a bakery. It also provided Histovery with relevant and reliable documentation.

His expertise has made it possible to assess the historical accuracy of the reconstructions.

Some locations have also been virtually recreated from ancient iconographic sources, such as an ingenious wooden mechanism that once carried water from the Meuse to the fortress.

Histovery, already known for its achievements at the Château de Chambord, the Palais de papes in Avignon and Fort Alamo in the USA, here signs a Walloon first, blending heritage, innovation and scientific rigor. A success that demonstrates, once again, the relevance of dialogue between experts at the University of Namur and socio-economic and cultural players.