Although Christians and non-Christians alike used graphic signs in late antiquity, the graphic signs considered in this volume are specifically the products of Christian cultures, both western and Byzantine. These include the staurograms, christograms (graphic signs consisting of letters from the name of Christ), monograms, and magic characters that appeared on late antique and early medieval manuscripts, coins, objects of daily life, cloth accessories, and public monuments.

Graphic signs, letter forms arranged into imagistic displays, invited literate, visual, and symbolic readings; essays in this volume particularly explore the ways that these signs operated as hybrid agents of communication, between men and men (as means of identification, signs of authority, and ornaments), between men and God (as pious means of invocation), and between men and supernatural forces (as signs with protective and intercessory properties). In the volume’s introduction, the hybridity of graphic signs suggests a central argument, that the use of these signs, which were neither fully letters nor images, was part of a larger movement toward abstraction in visual communication. Ildar Garipzanov has tracked extensively the increasing manifestation of abstract information and its relationship to visual cognition in the early Middle Ages, embedding his analysis within the theoretical framework of graphicacy – the ability to make and to interpret maps and diagrams as proxies for concepts. From 2012 to 2017, he was the leader of a project supported by the Research Council of Norway, »Graphicacy and Authority in Early Europe: Graphic Signs of Power and Faith in the Early Middle Ages (c. 300–1000)«; the book here under review emerged from this project.

The first of the volume’s three parts deals with the display of graphic designs in manuscripts. Larry Hurtado charts the nomina sacra as their abbreviated forms developed to display compositions of images and letters (2nd and 3rd centuries), in which he sees Christians’ endeavors to give their faith iconographic expression. Michael Squire and Christopher Whitton are concerned with the intra-textual insertions of the chi-ro or chrismon within Latin poems Optatian (early 4^th century) addressed to the emperor. They show that this motif articulated the distinction between drawing and writing, between Greek and Latin, and between Christological and imperial emblematics, thereby multiplying modes of signification and frames of references, and requiring audiences to shuttle between reading and seeing. In his study of the »Notitia dignitatum« (an early 5^th century text known only as a 1551-copy), Beat Brenk notes a parallel between the listing of all ancient Roman offices, which never mentions incumbents by name, and abstract depictions of emblems and insignia, which eschew figural representations, arguing that both modes of representation articulated the concept of institutional continuity. Departing somewhat from these essays and their emphasis on the visual, David Ganz’s consideration of display script found in Latin books of the mid-9^th century addresses writing in terms of its perception by the acoustic and palatable senses.

Graphic signs in archaeological contexts occupy the second part of the volume. James Crow discusses the unique and overtly sacred display of Christian symbols and invocative texts on the aqueduct bridge of Kursunlugerme in Thrace (early 5^th century), a long-distance water conduit to Constantinople. Positioned so as to be visible and legible, this decorative program would have been expected to ensure the structural stability of the building against earthquakes, apotropaically, and liturgically by creating spaces for intercessory processions. In her essay, Ine Jacobs also addresses the liturgical and apotropaic dimension of the cross graffiti that were carved or painted on many pre-Christian components of urban public spaces in the eastern Mediterranean. She argues that these crosses, which were initially produced in the 4th century to mark pathways for ecclesiastical processions and to effect inclusion into a space under Christian control, continued to proliferate even after Christian hegemony was established to ensure safety against supernatural dangers. Henry Maguire demonstrates that early byzantine ornamental designs achieved talismanic power through specific patterns of arrangements – collections of several designs, emphasis on a single one, and reiteration or combination of multiple motifs –, all of which appeared on papyri, floor mosaics, and terracotta lamps. The christograms on terracotta oil lamps from late Roman North Africa receive an in-depth contextual analysis by Caroline Goodson, who concludes that their use, far from being exclusively official conveyors of imperial and ecclesiastical authority, signaled participation in an inclusive Christian community and remained impervious to military conquests, theological controversies, and charges of heresy.

The final section of the volume addresses the presence of graphic designs on material signs of status and authority. Christopher Eger’s examination of late Roman and early Byzantine brooches, fibulae, and belt buckles raises questions similar to Goodson’s about lamps, namely, the extent to which dress accessories decorated with Christian signs marked official status. At the time of their appearance in the late 4^th century, Christian signs on dress fittings were small and ornamentally combined with profane motifs, and served as general protective devices; during the 6^th century, they functioned as official badges of rank thereafter to be displaced by monograms bearing dignitaries’ names. Ildar Garipzanov’s study of monograms on 5th- to 7th-century coins from the Latin West and Byzantium, argues that the general connotation of monograms as signs of aristocratic rank prompted their appearance on imperial coins but impaired their development as specific signs of imperial authority, while offering a significant mark of status for the rulers and cities of Germanic kingdoms to display on their coinage. In the volume’s final essay, devoted to Byzantine silks of the 6^th to the 11^th centuries, Anna Muthesius proposes a continuum between graphic (abstract) signs and metaphorical images on silks distributed to military and other officials or sent as diplomatic gifts to the west, arguing that such signs and images imbued the silks with imperial authority and with historical memory. Such memory served as an agent of communication, forging intercultural bonds among Christian rulers in keeping with Byzantium’s concept of a Christian commonwealth, and formulating iconoclastic topoi aimed at idolatry and pagan worship.

A broad range of media displaying graphic signs is fully treated in this volume through historiographic review, abundant illustrations, detailed contextual analyses, and well developed arguments. Given the variety of artefacts considered and the many disciplines providing methodological frameworks for interpretation, one is struck by the homogeneity of the conclusions reached. These bear primarily about the nature of the evidence that graphic signs present of the spread of Christianity in Late Antiquity, about their roles as mediatic tools for the formation of a particularly Christian visual and material culture, and about their effectiveness in propitiating supernatural forces. There is also consensus that the meaning and agency of graphic signs expanded beyond the bestowing of rank, and the communication of imperial and church authority. This emphasis on the constructive impact of graphic signs on social and cultural formation broadens the volume’s commitment to graphicacy. While the abstracted nature of graphic signs and their impact on cognition is generally addressed from the viewpoint of the visual, many essays also discuss the role of personal touch, for instance, in producing, wearing, and receiving graphically designed objects. In his essay, Maguire advocates that graphic signs not be approached solely as legible and conceptual designs but as actual operative devices yielding specific results. The present volume admirably showcases the performative dimension of material artefacts ornamented with graphic signs.