In 1316, several experienced master builders were summoned to the construction site in Chartres at the request of the cathedral chapter. They came from Paris. Serious incidents had recently occurred, although the edifice had been completed barely seventy-five years earlier. From the description of the observed “disorders,” it is easy to understand why the canons became alarmed and decided to seek the best advice, fearing that the situation might deteriorate further. In fact, the structural defects (rare as they are) known today had already begun to manifest in the decades following the construction of the Gothic cathedral.
What remains is an extraordinary document because it analyzes all the “weak points” of the edifice. Furthermore, it immerses us in the reality of a medieval construction site at the decision-making level: discussions among specialists, on-site observations, and visit reports. Although the terms of these reports may initially seem rather naive, they are, in fact, based on immediate insights of remarkable technical precision.
We are publishing this text from the chapter archives for the first time since 1900, when it appeared in the annals of the French Archaeological Congress. Until now, certain passages of the document had not been fully understood, but recent renovation work has clarified their references. As a result, several of the comments included here are entirely new.
Here is now the text of the expert report, in Old French – Capitular Register, ras. 1008, folio xxxv, verso (1314–1345)
« Anno Domini M CCC° decimo sexto, die Jovis post festum Nativitatis Béate Marie Virginis Sancte, fuit relacio defectuum ecclesie per magistros advisitandum dictos defectus deputatos per capitulum in modum infra scriptum » :
« In the year 1316, on the Thursday following the Feast of the Nativity of the Blessed Virgin Mary, the faults of the Church were presented by the masters chosen to study said faults, in the manner described below » :
« Vez ci les deffauz qui sont en l’iglise Nostre Dame de Chartres, veuz par mestre Pierre Chielle, mestre de l’euvre de Paris, par maistre Nicolas de Chaumes, mestre de l’euvre de Nostre Sire le Roy, et par maistre Jaques de LoncJumel, mestre charpentier et juré de Paris, en la présence mestre Jean de Reate, chanoine de Chartres, maistre Simon Daguon, mestre de l’euvre, mestre Simon, le charpentier, et meistre Berthaust, jurez de ladite euvre, dou commandement au déen ». (1)
(1) The experts are supported by the regular workers responsible for maintenance and development projects on the cathedral, all of whom are permanent employees of the chapter. We will not delve into the specific functions that Mr. Jusselin has clearly defined. [The Mastery of Work at Notre-Dame de Chartres, Memoirs of the Archaeological Society of Eure-et-Loir, Volume XV 1915–22, 231–243.].
Simon Dagon holds a broad responsibility over the entire structure and the various trades involved. All operations conducted on the cathedral fall under his purview, as stated in his official and remunerated status, although his exact level of technical expertise cannot be determined. In truth, Simon Dagon is primarily known for his legal troubles, particularly his dispute with a canon he insulted, Renaud de Boissy. The position appears to be hereditary, as Simon Dagon succeeded his father, Renaud Dagon, no later than 1303. Upon Simon’s death in May 1321, the role of master builder passed to his brother-in-law, Huguet d’Ivry. The decisions and expenses of the master builder were closely monitored by specially elected canons known as clerks of the works. These clerks, typically two in number, were tasked with oversight. Additionally, the works department seemed to benefit from a secretariat, particularly for accounting matters.
Simon the carpenter and Berthaut the mason were sworn craftsmen, meaning they were contractually attached to the chapter and responsible for directing all work within their respective areas of expertise. By the 15th century, the list of sworn masters also included a glazier and a blacksmith. Simon officially assumed his position on May 26, 1302, as recorded in the chapter’s register. In 1335, upon his retirement, he was granted a lifetime pension. Later, respecting his wishes, his children ensured that an office was held annually in the cathedral on the anniversary of his death, February 9.
Less is known about Berthaut (also referred to as Bartholomew) and his career. He is mentioned in a 1318 document concerning a customary clothing allowance provided to him. This document reveals that he was originally from Mainvilliers.
« + Prumierement, nous avons veu la vouste de la croez (1) : il i faut bien amendement, et qui ne li metra briefment, il y porroit avoir grant péril.
+ Item, (2) nous avons regardé, pour le profit de l’iglise, que le premier eschaufaut mouvra de desus l’ensmellement des verrières, pour faire la voste de la croez ».
« Seigneurs, (3) nous vous disons que les 1111 ars qui aident à porter les voûtes sunt bons et fors, et les pilliers qui portent les ars bons, et la clef qui porte la clef bonne et fort; et ne convenrra oter de vostre vouste plus de la moitié, là où l’an verra que mestier sera. Et avons regardé que l’eschaufaut movra d’audesus de l’enmerllement (4) des verriesres; et de cel eschaufaut se aidera on à covrir vostre lesteril (5) et les gens qui iront par desous, (6) et s’en aidera l’an à faire les autres eschaufaus (7) à faire en la vouste, ce que l’an verra qu’il convendra à faire et mestier sera. »
(1) Crossing of the Transept: Since the ribs of this vault share the same profile as those of the nave, and the keystone appears to be original, judging by the decorative motifs, it seems evident that only the infill compartments were repaired. As suggested by Mr. Bouttier, it is possible that the work did not involve the central quadrilateral but rather the bays immediately adjacent to the transepts.
(2) This paragraph is located at the end of the report, just before the discussion on the roof trusses, particularly regarding the chevet beam. We have moved it here to enhance clarity. It is likely the first contribution of Jacques de Lonjumel, a carpenter who appears to address all matters concerning his expertise towards the end of the report. This detail suggests the significance attributed to the issues surrounding the crossing. Initially, the intention is for him to confirm, following the mason’s statement, the feasibility of the scaffolding required for this large-scale operation.
(3) In the original document, this paragraph is placed before the introductory sentences (“vez ci les deffauz…”). The vault of the crossing is the main cause for concern, and experts are questioned about it right away, even before they have the chance to inspect the site and deliver a comprehensive report.
(4) Further on in the text, we read the term ensmellement. Today, it would be written as emmêlement (entanglement or interweaving). This term either refers to the filling of the high stained-glass windows, which seems unlikely, or to their surrounding structure. It most likely describes the arch – more precisely the “molding” – encircling the upper part of the small rose windows, doubling the vault panels. Regardless of the precise meaning of this term, it is clear that scaffolding was lowered from the vaults along the stained-glass windows through openings that can still be seen about 70 cm from the walls. Rather than scaffolding in the traditional sense, this setup resembled a mobile platform, akin to the ones used today for cleaning skyscraper windows.
(5) Villard de Honnecourt uses a similar term in his Album: “Ki velt faire 1 letris por sus lire evangille, ves ent ci le mellor manière que io face.” (Plate XII, folio 7, recto)
(6) We were already taking care to ensure the protection of: 1) the finely sculpted works, as was naturally the case for the rood screen; and 2) the public, to prevent any falling material or tools from causing an accident on the ground.
(7) The text remains quite vague regarding the methods used to install all the scaffolding. While it is clear how the hangers allow work along the periphery, near the walls, it is less apparent how they would enable access to the apex of the arch, close to the keystones. The experts merely specify that these hangers could be “utilized” to supplement the scaffolding as needed, depending on the work that may prove necessary.
It is unclear where the damage was located: whether it was at what we ourselves refer to as the crossing, or in the transepts (a different interpretation of the term “crossing”). Beams are embedded in the masonry of the vaults in these areas.
Next section: Expert Report – Flying Buttresses and Narthex Columns