Although precious stones constitute one of the most important ornamental elements of sacred scripture during the Middle Ages, their close association has never been systematically analyzed. As three-dimensional material entities mounted on the outer surfaces of codices, stones contribute to a transformation of the layers of written parchment into an object with sculptural qualities. With their vivid colors and translucent effects, they substantially shape the sensual appearance of the books that is crucial to their use in ritual performance. Going beyond a mere allegorical interpretation, this project takes into consideration the very material character and valence of stones, as well as their close – material and functional – relation to the book object they adorn, and its role in liturgy. Considering their intimate relationship with books also implies examining the stones in the context of the multi-layered ornamentation outside as well as inside the codices. It is especially important to examine the meanings that result from their careful placement and in particular from their interactions with the other ornamental components within the multi-material surface texture of treasure bindings, figurative images included. Special attention will be given to the use of colored glass “imitations”, which are less rare than has long been assumed, as well as to the integration of spolia in the form of intaglios, often from antiquity, and more rarely from other cultural contexts like Islamic cultures.

To gain a more comprehensive understanding, this study will also consider the economic, social and aesthetic spheres of activity linked to the production of these variegated compositions – ranging from the collection and donation of the stones to their arrangement. As the stone ornamentations were particularly prone to later changes, attention will be paid to evidence of repair and change in codices with complex object biographies. Indeed, the precise analysis and documentation of the state of preservation and any such changes are of utmost importance. In this regard, the project has an important partner in the Swiss National Museum and its Conservation Research Laboratory. In addition to existing material-scientific analyses, and in collaboration with the responsible institutions, analyses will be carried out on select objects from the 9th to the 11th century – the time period of special focus in this study – in order to examine their state of preservation and determine types of stone and glass. 

The picture above shows the golden front cover of the Codex Aureus of St. Emmeram (Munich, Bayerische Staatsbibliothek, Clm 14000), a Gospel codex produced at the court of Charles the Bald around 870. It is distinguished by an exceptional set of regularly arranged, high-quality sapphires and emeralds. Particular attention was given to the golden settings that work to semantically charge the gemstone adornment in a multi-layered way. Ubiquitous vegetal forms give the suggestion of sprouting and vitality, corresponding to contemporaneous ideas of animate forces or “virtutes” inherent in the precious stones. Moreover, the settings surrounding the representation of Christ in the center of the cover are reminiscent of chalices, which refer to the blood of Christ and thus to his presence in the Gospel Book. Arcade-like structures supporting the stones in turn allude to the apocalyptic vision of Heavenly Jerusalem, the paradisiac city decorated with gemstones; closely related to the codex they adorn, these arcades evoke the metaphor of the book as building, the actual codex containing the four Gospels thus being presented as sacred, “life-giving” space.

Researcher: Katharina Theil

Image Credit: Bayerische Staatsbibliothek, Clm 14000, front cover of the Codex Aureus of St. Emmeram


Precious manuscripts with purple-colored parchment skins and texts written in gold and silver are known to have been made since antiquity. Christian sacred scriptures thus embellished are first mentioned by Jerome, who harshly condemned the practice as unnecessary luxury. Regardless of this critique, purple manuscripts flourished. The embellishment of parchment with purple colorants is a defining trait of many manuscripts of the highest quality produced from the 8th to the 11th century. Recent advances in the technical analysis of the materials used to evoke purple have spurred new interest in the aesthetic of purple ornament and its development in Carolingian and Ottonian book production. Still, a comprehensive study of the multifaceted aspects of purple decoration in the manuscripts of this time period has yet to be carried out. This research project focuses on the stunning transformations purple ornament underwent from the 8th to the 11th century. It analyzes the various techniques and methods used to create the multi-sensory purple textures, and studies the contexts of this multi-layered ornamentation, taking a close look at the interactions between the text, the book objects, their liturgical setting, and their users.

In order to gain a nuanced view of the chronology and distribution of manuscripts with purple-colored surfaces and the contexts of their production, patronage, and usage, this project aims to establish a catalog of purple-decorated manuscripts from the 8th to the 11th century. Purple textures will be classified and put into context by studying their correspondence to content, structure, imagery, and script, considering the entire topology of ornamentation both within and on the outside of the individual books. Particular attention is given to hitherto insufficiently considered innovations, which use material correspondences to evoke purple surfaces, i.e. the evocation of textile and stone textures. The sensory effects achieved through such material textures will be examined in relation to contemporaneous ornament discourses and critiques, studying the interplay between decorative actions (such as dressing or polishing), text, and language in the liturgical performance of sacred scriptures. 

The image above shows a detail of the P-initial beginning the Gospel prologue “Plures fuisse” by Jerome on fol. 1r of the St. Riquier Gospels, now housed in the Bibliothèque municipale d’Abbeville (ms. 4). The manuscript comprises 189 purple-colored folios, all inscribed with golden ink. It was a gift from Charlemagne to his close advisor Angilbert, the abbot of St. Riquier, probably bestowed at Easter 800, when the emperor visited the newly rebuilt monastery. This makes it a precious document of the earliest phase of the adoption of purple-colored manuscripts at the Carolingian court, and exemplifies the stunning sensual quality of purple skins. As in nearly all purple manuscripts, the dye used to create the shimmering surface was not real Tyrian purple from the mucus of Murex snails, but a plant-based dye (in this case folium), here applied by pressing the parchment sheets between textiles soaked in this colorant. Some traces of the texture of these coloring textiles are still visible on the parchment surface. 

Researcher: Thomas Rainer

Image Credit: BnF Gallica, Quattuor Evangelia, dits Evangiles de Saint Riquier ou de Centula, Bibliothèque municipale d’Abbeville, Ms. 4, fol. 1r


Throughout the Middle Ages, precious metals were a crucial part of “high-profile” book ornament: they defined the “gold-standard”, so to speak, of a certain level of book decoration. Yet the way in which this standard was conceived of varied greatly in different periods and regions. In fact, no other component of book ornament could be applied in so flexible a manner: certainly, the use that has gained most attention from art historians is its employment as gold-ground in miniature painting. In Western book illumination, gold ground can be found from the late tenth century onwards, and may therefore be considered a relatively late innovation. Secondly, the modern notion of codices aurei or argentei refers to the ink used for writing the texts. Chrysography and agyrography were common techniques of precious book ornamentation in late antiquity and the early Middle Ages, often used in combination with purple dye for the ground of the pages. A third possibility for the use of precious metals is addressed when medieval sources call a book “golden” or “silvery,” expressions that usually imply that these precious metals were used for revetting the book’s exterior. 

Following the holistic approach of our research group, this project will undertake the first comprehensive investigation of golden books in the Western Middle Ages. Breaking with the traditional separation of individual practices of book decoration, we will examine different areas and techniques of golden book ornament in a comparative and synoptical manner. By doing so, our understanding of “golden books” and their specific concepts of material ornament will proceed beyond the traditional approach of material iconology. Among the objects that we will analyze, a first important group comprises the “very golden books” that combine the use of precious metals for the covers, the script and the illumination. Other, equally interesting cases are the result of practices that restricted the use of precious metals to individual areas of the book. As a third case, we will consider books from those book cultures that rejected the use of gold completely. And finally, books whose golden ornament has been subject to looting will be examined.  

As with so many lavishly decorated books of the liturgy, the main use of the early eleventh-century Uta Codex, shown above, seems to have been its carrying and display, without opening the book for reading: the pages of this lectionary are still in astonishingly good condition and do not show signs of wear. The primary “interface” for seeing and handling such a book was its spectacular and sophisticated binding. In the case of the Uta Codex, this was a book box in which the manuscript was locked. The monumental sculptural decoration in gold plate shows Christ as the ruler of heaven, enclosed in a wide frame decorated with gemstones, enamels and filigree, and equipped with his regalia: the mandorla, the throne and the book. The high relief of the golden surfacescape dramatically brings to the fore the role of the gospel book as a vessel for the incarnate Word. Christ is holding an object that seems to be a book whose encrusted golden cover resembles the jeweled golden book box. A closer look reveals that this binding contains no codex and is therefore a cover for Christ’s body itself. In direct keeping with this, Christ’s thumb incises deeply into the golden cover, thereby affirming the close interrelation between the incarnation and the inlibration of the Word in medieval Christianity.

Researcher: David Ganz

Image Credit: Bayerische Staatsbibliothek, Clm 13601, book box of the Uta Codex


The research project is located at a central interface between art history, book history, and the study of material religion. By focusing on the ornament of medieval books as a material practice, the aim of this project is to remove barriers that have stood in the way of a new understanding of the arts of the medieval book. Instead of the traditional contrast between material and representation, as well as text and illustration, the focus turns to a new holistic concept of ornament described by the medieval Latin terms “ornamentum”, “ornatus”, and “decorum”. Used in this sense, ornament is always related to what it embellishes; it presupposes an action of decoration that is executed on or around objects and persons. The research project will explore this relational nature of ornament in medieval manuscripts, thereby creating a new model for thinking about ornament and its role in material religion in a general sense. 


A working basis for all subprojects is the growing number of precious manuscripts that have been closely analyzed with regard to the material components used by medieval artists and scribes to produce these splendid objects. In cooperation with the Conservation Research Department of the Swiss National Museum, we will conduct our own technical analyses of material components when necessary. The data thus gained will be placed in a wider context in order to study all aspects of the multi-layered material textures of precious manuscripts from the 8th to the 13th century. A range of methodologies will be pursued to study questions of production, patronage, liturgical usage, display and care of the objects, as they pertain to different categories of medieval ornament.


To investigate the precious surface landscapes of medieval manuscripts, we have chosen four exemplary subcategories: gold and silver, purple, precious stones, and textiles. In all subcategories, we combine a close-up look at selected individual examples with a perspective that creates an overview of different geographic regions and time periods. Six questions common to the four subcategories are examined: 1) the topology, i.e. the distribution of the decorative elements and ornament on the three-dimensional body of the book; 2) the materials, techniques, and effects of the surface embellishments and their multi-sensory potential; 3) the art of writing – precious materials and script; 4) the iconicity of book ornament; and finally, 5) networks of actions and 6) discourses that determine the perception and semantics of the ornamentality of holy books.


The arts of the book are of central importance for the art history of the Latin-speaking world of medieval Europe. This project aims to establish a new approach to this field of research. In the early and high Middle Ages, decorated books were created not as neutral storage devices to secure texts meant for reading, but as sacred objects. The distinctive decoration of the books used both in the liturgy and for private piety is characterized by the use of precious materials, and the different modes of evoking such materials on the body of the book. The appearance of this decoration shapes the surface textures of sacred scriptures on the outer covers as well as on the inscribed and illuminated pages within the books.


Image Credit: University of Manchester, The John Rylands Library, Latin MS 98, fol. 154r