Musée provencial des Arts anciens du Namurois, Namur
Authors: Lieve Watteeuw (KU Leuven), Marina Van Bos, Ina Vanden Berghe, Maaike Vandorpe, Marie-Christine Maquoi (KIK-IRPA)
Research keywords: liturgical vestment, mitre, leather, textile, illumination, Jacques de Vitry, macro X-Ray Fluorescence scanning, high pressure liquid chromatography, optical and scanning electron microscopy, pigment, fibre, dyes, metal threads
The treasury of Oignies, kept in Namur is a splendid treasure trove of religious silverware, relics and valuable objects, dating back to the 13th century. The treasury is linked to the Augustinian Priory where Marie of Oignies stayed during her life ( Maria Ogniacensis, 1177-1213). Her friend, confessor and hagiographer Jacques de Vitry (c. 1165-1240) played an important role in the growing veneration for de saint woman and the wealth of the Priory. After becoming a dean of the College of Cardinals, Jacques de Vitry died in Rome in 1240. Before his death Jacques indicated that he wanted to be buried at Oignies, near Marie, and he endowed the priory with 1,500 silver pounds, silk textiles from the Orient, his personal ecclesiastical ornaments, relics of saints, and a large number of books. According to his last wishes, his remains were transferred to Oignies, where they were placed next to the blissful Mary of Oignies. The community cherished the remains of the saint and Jacques de Vitry carefully during centuries. After the destruction of the priory of Oignies during the French Revolution, the treasure was entrusted in 1818 to the Sisters of Our Lady of Namur. In 2010 the treasury became part of the collection of the King Baudouin Foundation. Several items from bishop Jacques de Vitry are still in the treasury of 0ignies: a portable altar, two bishop's miters, a maniple, a part of an ivory cross, and two episcopal rings with sapphires, all parts of the bishops ecclesial ornaments.
One of the most remarkable pieces is the illuminated parchment mitre, a rare early medieval liturgical vestment. The mitre is composed of illuminated parchment strips with representations of Christ, the Virgin, religious symbols, angels, apostles and saints. On request of the King Baudouin Foundation and the Société archéologique de Namur, the mitre was closely studied during conservation treatment by an interdisciplinary team at KU Leuven, in the Book Heritage Lab in the Faculty of Theology and Religious studies in 2017 - 2018 in the context of the CROMIOSS project and in collaboration with KIK-IRPA. The iconographical outline seems to support the theory of Joseph Grevek (1912), Christian Cannuyer (1994) and Jaroslav Folda (2005) that the mitre was commissioned by Jacques de Vitry himself. The scenes and figures accentuate his status and power as bishop of Acre. The vertical illustration on the front of the mitre confirms his relationship to God; the vertical illustrations at the back of the mitre legitimises his ecclesiastical authority, as do the twelve Apostles depicted on the horizontal register. Their presence associates Jacques de Vitry with these first bishops of the Church. The ornamentation of the mitre is rich, but executed in unusual materials and techniques. Embroidered mitres were more common in the 13th century, but the choice for parchment and illumination is certainly original and confirms the acquaintance of Jacques de Vitry with the flourishing art of Paris book illumination in this period.
The full results of the research: Lieve Watteeuw & Marina Van Bos: A manuscript for the head: The study and conservation of the thirteenth-century illuminated parchment mitre of Bishop Jacques de Vitry, Care and Conservation of Manuscripts 18, Copenhagen, 2023 ( Forthcoming)
A part of the research of the mitre of Jacques de Vitry was carried out within the framework of the ARTGARDEN project. The technical-material analyses are carried out non-invasively (if possible) or after taking micro-samples.
The painted parchment was analyzed with a macro X-ray fluorescence scanner, always taking into account the fragile state of the mitre in general and the parchment in particular (very patchy areas, wavy parchment,...).
The results of the MA-XRF analysis can be represented as distribution maps of individually identified chemical elements.
The gold, calcium and iron distribution maps, being almost identical to each other, illustrate the similarity with the application of gold in illuminated manuscripts: the gold leaf is applied on a gesso (a calcium-based layer colored with red iron oxides) before the other colors.
The figures are painted, partly on this golden background, in red (red lead), blue (ultramarine), green (copper-based), brown (organic), black (carbon black) and white (lead white).
The outline lines are painted with iron gall ink, a brown-black ink used as writing ink in manuscripts, mainly from the 10th century onwards.
The extensive use of gold and ultramarine signify the luxurious character of the mitre.
The non-destructive examination by digital microscopy not only illustrates the details of the paint layer but also documents the complex composition of the parchment mitre. The background is formed by white leather on which is a beige silk cloth covered by polychrome decorated parchment. The whole contains a red lining. The reverse side contains a central decoration formed by a structure of metallic and green threads. The pennants with multicolored fringes are made of decorated parchment covered on the reverse side by a red lining. On the front side, black thread ribbons are present.
Micro-invasive analysis for this type of multilayered object is mainly limited by the possibility to collect a sample. However, due to the poor condition of some fragments, a few micro-samples could be collected. The identification of the fibers is based on the examination of the fiber morphology by optical microscopy in transmitted and/or polarized light. The dye composition is analyzed by high pressure liquid chromatography coupled with a photodiode detection system (HPLC-DAD). A complete examination of the metal thread composition, identifying not only the metal but also the potentially present textile core, dyed or not, is carried out using scanning electron microscopy and energy dispersive X-ray detection (SEM-EDS). This gave the following results:
The threads of the highly degraded beige / uncoloured main fabric, have been identified as degummed silk (Bombyx mori L.) filaments. The red lining fabric is also composed of silk, colored by the use of madder root (Rubia tinctorium L.). The brown-black remains of a small ribbon on the outside of the fanons were dyed black with tannins and ferrous sulphate and alum, a known method until the late 18th century. However, the use of iron sulphates had disastrous effects on the silk, so that these black ribbons have almost completely disappeared today.
The green/ochre yarns forming part of the central decoration with metallic threads were dyed with a combination of blue and yellow dye sources. Based on the presence of the compounds indigotin and indirubin, the blue source is either indigo (Indigofera sp.) or woad (Isatis tinctoria L.), and the detection of the yellow compounds luteolin and apigenin indicates the use of plants such as weld (Reseda luteola L.), sawwort (Serratula tinctoria L.) or chamomile (Anthemis sp.).
The metal thread sample taken from the central decoration consists of a silver lamella which has been gilded on the outer surface. This strip has been wound in the s direction around a textile core of silk threads. The central silk thread was almost completely covered by the silver lamella. It was dyed yellow with weld, sawwort or chamomile. The current dark color of the metal is due to corrosion caused by the formation of silver chlorides. This type of silver thread (guilded or not) was well known in the Middle Ages.
The results of the research have been presented:
- Vanden Berghe, I. and Van Bos, M., "Macro XRF-scanning: New opportunities for non-destructive analysis of the episcopal mitres attributed to bishop Jacques de Vitry (12-13th c. AD), two masterpieces of the Walloon Region", at the "Non-destructive and microanalytical Techniques in Art and Cultural Heritage International Conference (TECHNART)", Bilbao, May 2-6, 2017.- Vanden Berghe, I., Van Bos, M. and Vandorpe, M., "The Relic Treasure of Oignies - Dyestuff and Metal thread study of the textile fragments of two unique episcopal mitres", at the international workshop "Labs, Art and Relics", Royal Library of Belgium, November 22-23, 2018.
 On Marie of Oignies and Jacques de Vitry, see: Monica Sandor, 'Jacques de Vitry: Biography', in De l'homélie au sermon, eds. by Jacqueline Hamesse and Xavier Hermand (Louvain-la-Neuve: Publications de l'Institut d'Études Médiévales, 1993), pp. 53–59; Monica Sandor, 'Jacques de Vitry and the Spirituality of the "Mulieres sanctae"', in Vox Benedictina 5 (1988), pp. 289–312; Maria Grazia Calzà, 'Die Begine Maria von Oignies (†1213)', in Der hagiographischen Darstellung Jakobs von Vitry (†1240) (Würzburg, 2000); Brenda M. Bolton, 'Mary of Oignies: A Friend to the Saints', in Mulder-Bakker, ed., Mary of Oignies (Brepols, Turnhout, 2005), pp. 199–220.
 Robert Didier and Jacques Toussaint, 'Trésors des Soeurs de Notre Dame a Namur: Catalogue critique', in Autour de Hugo d'Oiginies,(Namur, 2003), pp. 267-269 and 272-280.
 The treasure is being deposited at the Société archéologique de Namur and exposed in TreM.a (Musée des Arts anciens du Namurois). It has some fifty pieces made by the silversmith Brother Hugo d'Oignies (1187-1240) and his collaborators. On the treasury of Oignies, see: https://oignies.collectionkbf.be/fr; Collet, Emmanuel. Le trésor d'Oignies, King Baudouin Foundation, Brussels, 2012; Philippe George, Reliques et arts précieux en pays mosan. Du haut Moyen Age à l'époque contemporaine, Liège, Éditions du Céfal, 2002; Le trésor d'Oignies et le frère Hugo, Exposition. Nivelles. Crypte de la collégiale Sainte-Gertrude, 1963.
 Namur, SAN, Parchment Mitre of Jacques de Vitry, ca. 1220?, tawed leather, painted white silk, illuminated parchment, later added red silk and black galloons. Measurements: headpiece mitre: 22 x 28 cm, lappets: 58 x 5,5 cm. The CROMIOSS project from SAN, Namur (www.lasan.be/la-recherche/projet-cromioss) was funded by the Fund Jean-Jacques Comhaire of the Fondation Roi Baudouin (FRB), Belgium. The results of the CROMIOSS project were presented at the international colloquium 'Labs, Art and Relics', 22 and 23 November 2018 in the Royal Library of Belgium