Olivier Guyotjeannin is a French medievalist historian, professor at the Ecole des Chartes since 1988 where he teaches diplomacy and medieval Latin . A former pupil of the Ecole des Chartes, he defended a thesis in 1981 on “The seigneury of the bishops of Beauvais and Noyon (10th-13th centuries). Due to his training as an archivist-paleographer, his work gives a major place to the study of medieval sources and their use by medieval historians In this perspective, he is the author of several works for historians in which he endeavors to establish a methodology for approaching sources . It is with this in mind that Olivier Guyotjeannin begins Sources of medieval history.
The author wants to be both pedagogue and synthetic by delivering a " quick introduction intended for the beginning historian [in order] to perceive, behind the finished works (...) the nature of the materials which support their reflection ". The work is thus an immersion in the profession of the historian confronted with various sources that he must literally decipher, transcribe, translate, analyze in order to finally be able to provide a critical and constructive perspective.
A methodological approach
First, the author draws up a historiographical assessment - from the 17th century to the present day - on the use of sources by “historians”. Thus, we can see that, at the beginning, the integration of sources in the work carried out did not have the quasi-systematic character that we know today. Thus, many works of the modern era ignore in part - or completely - documentary series inherited from the Middle Ages. However, Olivier Guyotjeannin mentions some precursors who seem to pay particular attention to certain discoveries (the tomb of Childeric discovered in 1653) by exploiting them, like the congregation of Saint-Maur or the scholar Dom Jean Mabillon who, in 1681, wrote a fundamental treatise on palaeography . Subsequently, the author shows how, in the 19th century, a historiographical turning point occurs - notably thanks to the German school - when the sources begin to be the subject of large census undertakings, thus facilitating their conservation. Consequently, this careful taking into account of the potential of sources for the historian, will push - at the beginning of the XXth century - certain historiographical currents to reject documents judged "false" or to neglect certain sources considered as "too narrative". However, in the second half of the twentieth century, what Jacques Le Goff calls the “documentary revolution” occurs. Thus, the idea is born that the historian must "go all out", not neglecting anything and integrating into his work everything that had been neglected before. In order to illustrate his point, the author completes this historiographical panorama by mentioning two sources: an “authentic” act and an act recognized as “false”. The aim of his demonstration is both to show on what elements the historian can base himself on to distinguish a "true" from a "false", but especially how the two documents can be exploited. The "fake" then appears as qualitatively as interesting as the authentic act, insofar as it provides information - among other things - on its production context and on the forger's intentions.
A historiographical approach
Subsequently, Olivier Guyotjeannin focuses on the conditions of production of textual sources in order to clearly perceive that beyond what he says, a document can provide information on various elements. The author begins by investing the field of what he calls the “treasure of words”. Thus, it delivers a panorama of the multiple languages encountered within the medieval West. The very study of these languages can then prove to be instructive and provide the historian with material to broaden the field of his investigations. The author demonstrates the diversity - within a single language - which can be observed and which provides rich information to which the historian must pay attention. For example, Latin does not constitute a “fixed and timeless block”, but follows an evolution over time and space. Subsequently, the author highlights all the potential that the historian can exploit by being interested in onomastics. Rich in information, the names are strong cultural markers which can highlight the Roman, Germanic or Christian legacies and which the Middle Ages inherited to, sometimes, carry out original creations. In the same perspective, the study of toponymy could be instructive as regards the evolution of land use and, more generally, of the historical context. The author does not fail to point out that the historian, if he wants his work to be relevant, must above all cross the different types of sources which are available to him. Still in the same chapter, the author is then interested in the evolution of supports and more particularly of the passage from papyrus to parchment. Beyond this historiographical event, Olivier Guyotjeannin underlines the major role of copyists who at the same time allowed the transmission of entire sections of several works, while sometimes proceeding to deformations which, over the centuries, resulted in producing counter - sense compared to the originals. Thus, all the work of the historian will consist in studying these mutilations in order to clarify their meaning while striving to find the original. A history of the book must then be undertaken by carefully studying storage places such as libraries or archives. In the end, a series of documents - given in their original version and translated - illustrate the author's words. Thanks to three acts of chancellery from the 8th to 15th centuries, we can thus observe the evolution of Latin, which allows itself to be influenced by the vernacular languages.
Contextualization of sources
In a third part, Olivier Guyotjeannin focuses on the production contexts. We can then realize the difficulties encountered in the dating of a textual source. Medieval authors in fact adopted various “computes”, which today's historian must master in order to place the documents in their respective contexts. Birth of Christ, reign of a sovereign, significant event, so many “points of beginnings” to which the authors can refer to date their writings. In another spirit and by referring to the rise of the Investigations or the Inquisition, Olivier Guyotjeannin tries to highlight the increasing probative part that the written word tends to occupy throughout the Middle Ages. This marker of truth that the writing tends to guarantee - just like the seal to another extent - can lead some authors to make their story more complex by making the statement more and more narrative, with a view to "making it true". Thus, in these seemingly uninformative sources for the historian of mentalities, the author demonstrates that here too, valuable information must be analyzed and taken into account. Subsequently, the author evokes the vagaries of documentary conservation and shows how, from the 12th century, a “memory consciousness” slowly emerges and thus favors the creation of specific places of conservation, the archives. However, the vicissitudes of history sometimes severely mutilate documentary series. The author takes for example the great fire of 1737 of the Ile de la Cité or the revolutionary movement of 1789. Thus, the historian must be careful of the representativeness of the sources at his disposal. Finally, the author delivers a brief typology of sources supplemented by a selective bibliography, allowing the beginning historian to go further in these issues. This also allows the historian who approaches new sources to have a "reading grid" facilitating his first approach. Thus, Olivier Guyotjeannin distinguishes historical texts (History, Chronicle, Annale, biography ...), hagiographic sources, writings relating to worship and devotion (customary, sermons, penitentials ...), law and jurisprudence, acts of the practice (diploma, charter, cartulaire ...), management documents, communication tools (letter, propaganda literature ...) and finally literary and scientific texts. Each category is supplemented in the appendix by a document commented on by the author.
In the end, the work of Olivier Guyotjeannin will be of great use to the novice historian wishing to acquire the bases of a knowledge put aside for too long. The sources of medieval history work like a textbook to refer to before approaching the study of sources too head-on. In addition to providing a general overview, the author's words will be of particular interest to the historian who will be able to benefit from the experience of archivist-paleographer Olivier Guyotjeannin, daily confronted with medieval sources and therefore with the problems encountered. However, we may regret the little space given to epigraphic inscriptions which, however, should be included in the rank of textual sources. Indeed, the latter can be of interest just as important for the historian as a charter or a diploma. However, it seems today acquired, following numerous works including that of Robert Favreau , that the character of "universal publicity" that the medieval inscriptions cover cannot be put aside. Thus, we regret the absence of any mentions made, for example, to the campanar inscriptions, to the funerary stelae or to the tombstones. The other reservation concerns the “brief typology” proposed at the end of the third chapter. Indeed, this desire, certainly salutary but sometimes reductive, to classify a document in a category has the main fault of locking the historian into a preconceived reflection and, in fact, of pushing him to only partially exploit all the substance offered. by the improperly "classified" source. However, the work of Olivier Guyotjeannin remains an excellent introduction to the subject which should be supplemented by other works of the same genre . Moreover, the author offers a quality indicative bibliography to refer to for further knowledge.
Olivier GUYOTJEANNIN, Sources of medieval history, The Pocket Book, Paris, 1998, p.9-221
 http://www.enc.sorbonne.fr/professeur/olivier-guyotjeannin (consulted on 01/25/2014)
 O.GUYOTJEANNIN, J.PYCKE, B.-M TOCK, Medieval Diplomatic, Turnhout: Brepols, 1993
 Dom Jean MABILLON, De re diplomatica, 1681
 R.FAVREAU, Medieval Epigraphy, Turnhout: Brepols, 1997
 B. MERDRIGNAC and A.CHEDEVILLE, Auxiliary sciences in the history of the Middle Ages, Presses Universitaires de Rennes, 1998