Some Thoughts on Glass in African Archaeology: An Introduction

Introduction

The history of this collection of articles on glass dates to 2020, when one of us (Babalola) proposed a symposium on Glass in African Archaeology for the meeting of the Society for Africanist Archaeologists (SAfA) scheduled for Oxford, but eventually held virtually in 2021 due to the Covid-19 pandemic. Although the withdrawal of several panelists led to the cancellation of the symposium, new contributors were galvanized to make this set of articles possible. One result of this reorganization was to move away from the Egypt-centered discussion of archaeological glass in Africa to examine what unfolded elsewhere across the continent and beyond, and the dynamic relationships between the people and glass as a material and object.

As a material, glass represents one of the most sophisticated technologies invented by humans in antiquity. Studies of glass have focused on the nexus of production, exchange, and consumption in past societies. For decades, issues relating to production have significantly concentrated on ancient Egypt, where the earliest evidence of glass in Africa emerged over three millennia ago (Rehren & Rosenow, 2020). This discussion tends to connect Egypt with the Middle East and the Mediterranean rather than with the rest of Africa. In contrast, research on glass in Sub-Saharan Africa has been energized by the desire to connect this region to the wider world under the rubric of regional and global interaction, on the one hand, and its socio-cultural significance, on the other hand. While understanding these questions is essential to glass studies, scholars tend to pay most attention to when and where questions, which leverage investigations of glass origins.

These efforts at origin tracing have been amplified in recent years by the application of Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) for elemental analysis of archaeological glass. Of course, elemental analysis is essential for an in-depth study of glass as it helps to reveal some nuances about the makers’ technical decisions. The chemical signature can also contribute to our knowledge of the ritual practices involved in the recipe preparation. For example, questions on why certain materials were included could be answered using the glass chemistry (Ige, 2010). These topics tend go undiscussed in many works on archaeological glass in Africa.

Against this backdrop, this collection on archaeological glass in Sub-Saharan Africa brings together recent research across the continent to provide refreshing insights, foster diverse perspectives, and push the boundary of glass studies beyond questions of origins. What role did glass play in the rise of complex societies? How did Africans technologically engage with glass as a material? How can we define the boundary between imported glass technology and local ingenuity? What relationship existed between glassmakers and artisans of other crafts? How was glass making/working organized? What role can ethnography play in understanding glass making/working in the past? The articles address these questions by engaging old and new archaeological, historical, and ethnographic data to explore the multivocality of glass in archaeological contexts across African societies through an approach that transcends descriptive reporting and compositional analysis. Among other things, it is imperative to interrogate the nuances of transforming glass from a material to an object. As Miller (1987, p. 129) opines, the “medium of objectification matters,” and to understand this medium, echoing Meskell (2005, p. 2), requires a “refashioning of archaeology to embrace more nuanced studies of our objects worlds.” Thus, this collection of articles aims to refashion data on archaeological glass to broaden our knowledge of Africa’s past engagement with the material.

For millennia, glass has fascinated humans with its beauty, its almost magical versatility in shape and color, and its ability to carry multiple meanings and signify concepts too complex to articulate in words. Compared to other artificial materials from antiquity, such as plaster, cement, ceramics, and metals, glass is the least utilitarian but most strongly linked to beauty, decoration, and the adornment of the human body. While various metals also offer a range of colors and other esthetic properties, such as sound, weight, and even smell, and amenable to personal adornment and ostentatious display, glass offers a much wider and more striking range of colors and brilliance. These characteristics of glass enable playful artistic expressions without the “dark side” of metals being used for weapons of war and destruction. It is, therefore, time to recognize glass as a pinnacle of human inventiveness and creativity and celebrate this material as a deeply humane aspect of our cultures, linking the material and spiritual worlds. Fitting with the International Year of Glass announced by the United Nations for 2022, this collection reflects some of the current, extraordinary scholarship on glass in Africa.

Outline of the Collection

Five articles in this issue cover the northeast and southeast Africa regions, from northern Nubia through Ethiopia to Tanzania and Malawi, while the sixth addresses glassmaking in central Nigeria. Most of the papers concern finds from the second millennium CE, though the paper on glass finds from Nubia spans nearly three millennia from the Egyptian New Kingdom through to the Roman and early Byzantine periods. Collectively, these papers illuminate glass trade and use in one of the key zones of cultural interaction between Africa and its surrounding regions, from the roots of glassmaking in Egypt some 3500 years ago to the heyday of glass bead use in Africa in the second millennium CE.

First, the article by Then-Obłuska and Dussubieux on glass beads from northern Sudan demonstrates, for the first time, the presence of Late Bronze Age Egyptian glass linked back to a New Kingdom tomb near the Second Cataract of the Nile. A bead from the 25th Dynasty was also found in the same region. These finds are not surprising, given that this Nubian dynasty ruled much of Egypt from the eighth to seventh century BCE. Beyond these isolated examples, large numbers of glass beads only began to appear in northern Sudan in the mid-first millennium CE. From the Late Roman to Byzantine periods onward, multiple compositional glass groups from the Middle East and South Asia dominate bead assemblages, reflecting the geographical position of Nubia along one of the main trade arteries of Northeast Africa.

Continuing up the Nile and turning east into the Ethiopian Highlands, the article by Marin-Aguilera and Dussubieux presents fascinating perspectives on the cultural meaning and connotation of glass beads in a highly intercultural, medieval context. Interestingly, most beads in this region seem to originate from the Middle East rather than the Levant or Egypt, with others coming from Asia through the Indian Ocean trade. The decisive information on the provenance of the bead glass comes from the LA-ICP-MS analyses. Moving beyond simple questions of provenance for this diverse assemblage, the authors take their interpretation further by contextualizing the entanglement of the funerary experience with the kinesthetic and haptic aspects of these exotic beads as embodiments of the Shay collective identity, and part of their resistance against their expansionist Christian and Islamic neighbors.

The next article concerns glass beads from Tanzania. The extraordinary discovery of an early second millennium CE glass bead workshop in northern Zanzibar demonstrates that the craftspeople there were fully capable of manipulating and shaping a range of glass compositions to suit their needs and preferences, as well as those of their patrons, rather than relying on finished glass bead imports. Henriette Rødland identifies four distinct types of beads, including widely known opaque yellow and red beads and previously unknown transparent teal and opaque green beads. This unique signature opens the possibility of linking this workshop to a broader distribution of beads along the Swahili Coast and beyond, even without chemical analyses. It is also possible that the workshop was a regional center for glass bead distribution. Further archaeological investigations at the site and adjacent locations may be pivotal for better understanding the nature and function of this glass bead-making workshop.

Further down the coast of Tanzania, Marilee Wood et al. examined a large bead assemblage from a mid-second millennium CE site in the Kilwa archipelago. Based on LA-ICP-MS analyses of some 140 beads, they identify a variety of glass compositions, including the first finds outside of India of two glass compositions specific to Rajasthan, and well-dated imported Chinese glass beads, overlapping with the earliest imported European beads around 1600 CE. Similar to the site of Mkokotoni in northern Zanzibar (Rødland, this issue), there are strong indications for local glassworking and bead production, further underlining the wide-ranging expertise and activity of local craftspeople across Sub-Saharan Africa during the second millennium.

Continuing a focus on European trade beads, Laure Dussubieux et al. look inland to explore their occurrence in rockshelter sites in Malawi. These beads represent indirect contact because Europeans only reached the region in the nineteenth century. As the authors point out, this part of Africa is not well covered by analytical studies of glass beads. Thus, their paper makes an excellent case for the interpretative power such studies bring to archaeological and historical research. They complement and go beyond what historical narratives have to offer, which are often biased by the agenda and interests of the narrators, and rather generalized in their tone.

The final article on this conceptual clockwise journey around Africa brings us to nineteenth-century central Nigeria, where Lesley Lababidi et al. investigate indigenous glass-making recipes and practices using ethnohistorical methods combined with chemical analyses of various raw materials, intermediate products, and finished objects. Situated at the interface of working imported (presumably European) bottle glass and making glass from scratch, indigenous glassmaking was last recorded here some 60 years ago. Thankfully, the amazing evidence for this unique traditional craft has been recorded and documented as part of the British Museums’ Endangered Material Knowledge Program (The Lost Legacy of Bida Bikini: A Documentary, https://www.youtube.com/watch?v=sTRxORja4Ik). The article does a fantastic job of presenting some information from this program to enrich the analytical data from both historical and recent experimental materials. On the one hand, comparing the process of glass making in Bida with what unfolded further south in eleventh-century Ile-Ife (Babalola, 2021; Babalola et al., 2018; Lankton et al., 2006) demonstrates the effectiveness of ethnohistory for archaeological interpretation. On the other hand, it reveals how little we know about glass making and working in Africa.

Taken together, these articles do more than highlight the transcontinental importance of glass in modern archaeological research—they reveal trade connections and craft developments well beyond what historical sources tell us. From a technical viewpoint, this collection is also significant for showing the importance of LA-ICP-MS (Freestone, this issue), which has rapidly ascended over the past decade or so to become the routine and standard method of glass analysis.

This latter observation stands out. The history of bead research is almost as old as antiquarianism, and generations of scholars have devoted their lives to developing complex typologies (e.g., Beck, 1928; Guido, 1999), detailed distribution maps, and chronological sequences of the use of beads. After some early analytical work (Davison, 1972), it took over a decade before SEM–EDS analysis of glass beads became routine and the established method of choice. These analyses typically captured a dozen oxides, with detection limits of around 0.1 to 0.3 wt% or 1–3 parts per thousand (1–3 per mil). The chemical data obtained from these analyses for the first time enabled us to document systematic differences in glass compositions and to identify the most likely raw materials for most compositional groups. As a result, we were able to distinguish different colorants and identify whether the base glass was made using plant ash, wood ash, or mineral natron. These compositional glass types, in conjunction with a rapidly growing body of analytical data from glass objects from the Mediterranean, South and Southeast Asia, and Europe led to the identification of likely production origins of the glass used to make the beads, wherever they were found. Based on these origins, the reconstruction of trade links became possible. The growing realization that glass, particularly as beads, is a highly mobile material began to show the interconnectedness of African societies, with increasing evidence of Indian glass beads playing a major role in East and southern Africa.

It took another few decades, though, until the increasing use of Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) opened a window into the world of trace elements in glass and the vast potential they hold to refine not only the discussion of raw material identification and the geographical origin of well-defined compositional groups, but also enabled the recognition of recycling, the use of specific colorants, and even the identification of objects made from the same batch of glass the same day in the same workshop (Freestone et al., 2009; Rehren & Brüggler, 2015). With some 55 elements now being routinely analyzed, down to concentrations well below the single part per million, in a matter of minutes, this new method is the current gold standard of chemical glass research. This increase in sensitivity by four to five orders of magnitude went hand in hand with a massive reduction in sample size. Where classical analyses, whether based on X-ray fluorescence, atomic absorption, or scanning electron microscopy with energy-dispersive spectrometry, required the removal of a certain amount of material to be processed for analysis, either as a polished block for SEM–EDS and its big brother EPMA (Electron Probe Micro-Analysis) or for dissolution for either of the other methods listed above, LA-ICP-MS blasts just a tiny crater into the sample and analyses the resulting vapor. The crater is so small that it is invisible to the naked eye. Through clever handling, the analyst can even ablate the corrosion layer before starting the actual data acquisition once the un-weathered glass core has been reached.

This is not the place for a full bibliographic study of the emergence and spread of this revolutionary technique in African glass bead research. Suffice it to say that five of the six papers in this collection are substantially based on LA-ICP-MS data. Also notable is the key role played by the Elemental Analysis Facility at the Field Museum of Natural History in Chicago, IL, under the stewardship of Dr. Laure Dussubieux, lead or co-author of four of the papers in this collection. Undoubtedly, Dr. Dussubieux is the leading analyst and knowledgeable go-to person for glass compositions in Africa and South and Southeast Asia—the key areas for glass consumption and production covered in this issue—but her expertise also extends to the Americas (Dussubieux & Walder, 2022). The data in the fifth paper using the LA-ICP-MS analyses was generated by Dr. Bernard Gratuze, the pioneer in applying this method to glass (e.g., Gratuze et al., 2001) and doctoral advisor of Dussubieux. Our understanding of glass production, working, and movement has been given a major agenda-setting boost by these two scholars’ professional dedication to method development and data quality, personal openness for collaborations, and vast overall expertise and willingness to share data. This commitment is comparable only to that triggered by the “godfather” of chemical research on ancient glass, Dr. Robert Brill, who, from joining the Corning Museum of Glass in Corning, NY, in 1960 to his passing in 2021, devoted his entire professional career (and beyond) to the advancement of our understanding of glass compositions (Brill & Koob, 2021; Freestone, 2021). Much of the high-resolution interpretation visible in these papers would not have been possible without LA-ICP-MS data. This collection of papers is a milestone in tracking instrumental progress and increasing the availability of this method. It is also gratifying to see that the African Archaeological Review is open to publishing this type of research, illustrating the ongoing integration of archaeological sciences within mainstream archaeology (e.g., Martinón-Torres, 2018).

What is promising about the articles in this issue is the creativity of the authors to infuse African agency into their interpretations of the data from glass beads. However, the limited number of papers on glass indicates the challenge still facing the study of this material in Africa. Undoubtedly, Egypt is at the forefront of discourses on the global history of glass technology, innovation, and spread. The recent studies in southwest Nigeria on high lime, high alumina glass have demonstrated the independent invention of glass technology in Africa (e.g., Babalola et al., 2018; Lankton et al., 2006). This is not surprising, as each region of the continent has a rich and complex history, we must be careful not to generalize the revolution and evolution of glass in Africa. Was Ile-Ife the only Sub-Saharan African city that invented glass? How many times was glass invented in Africa? How can we trace the transfer of glass technology in Africa? How do we understand the fusion of imported raw materials or technologies with local recipes and traditions, if there were any? The paper by Lababidi et al. (this issue) touches on aspects of these questions, but more research is needed to address them properly. The under-researched areas of glass studies in this issue do not, however, diminish the incredible work and innovative interpretations of the authors. Instead, they challenge us to do more in Africa.

Why Does this Research Matter?

The research presented in this collection highlights just one aspect of the extraordinary inventiveness of African societies and their artisans. The deep trade connections, evident from these studies, show that Africa was far from an isolated “dark continent” but traded widely to Europe in the north, to the core of the “Old World” in the northeast, and as far as China in the east, even if its own exports often did not always leave a clear record in the archaeology of those external regions. More importantly, it shows the skill and ingenuity of African craftspeople, working imported glass into new shapes and forms, using their own techniques to imbue this material with new meanings and social significance. Although little emphasized in these papers, there is growing recognition that African craftspeople could also make glass from raw materials, demonstrating a technological agency and independence that has historically been denied or even suppressed in political and academic discourse from the Global North. There are growing—and increasingly successful—calls to repatriate Africa’s looted material culture, as part of its tangible heritage. Similarly, this collection of papers brings home some of Africa’s intangible heritage, namely a recognition of technological achievements in mastering a material that is deeply meaningful for many of its societies. It also shows that “Africa” is the ultimate collective noun in that it looks singular but, in fact, represents a vast complexity and plurality of individuals, groups, cultures, and societies, each with their own achievements, expressions, and histories. Each adopted or developed glass differently and appropriated this material into facets of their culture and traditions in accordance with local values.

To use a recent story from the international art market as a metaphor, the scholarship in this collection of papers is reminiscent of what happened with Leonardo’s Salvator Mundi (The Guardian, 2021). Painted around 1500 CE, it was long thought lost or destroyed, with only copies surviving. In 2005, one of these paintings was bought at auction for about $1200, clearly seen as a low-quality work of unknown authorship. Less than a decade later, after careful restoration and research identified this as the original work by Leonardo, this same painting sold for $75 M in a private sale, then fetched a mind-boggling sum of $450 M at an auction in 2017. It was the same painting, concededly with substantial restoration work. What, then, explains the exponential increase in monetary value? The answer is simple: the proper attribution of specific authorship and carefully orchestrated hype to lure in the high-rolling patrons of these auction houses.

How does this tale relate to the papers here? Collectively, and building on the rapidly growing body of scholarship of the past 20 years, they give proper authorship to the cultural heritage embodied in African glass, recognizing the true skill and expertise of African craftspeople and giving them their long-disputed agency and authenticity. What we are witnessing is not an increase in monetary value, but something even bigger—an increase in social value and recognition for the 1.2 billion people living in Sub-Saharan Africa as direct descendants of the makers and users of these artifacts.

We would like to remark on one other aspect emerging from this research in this issue, which is the importance of archaeological science for modern societies. The most visible and iconic items of African art (mostly copper-alloy objects) found in museums and private collections are studied and venerated as cultural heritage. However, these objects represent only a fraction of past societies, typically being fashioned for and used by the elite. In contrast, the humble glass beads featured in these papers were available to a large proportion of society. The study of these objects thus gives voice to people otherwise unheard in historical discourse by focusing on their lives and dreams (rather than ours) of owning something beautiful, colorful, and highly personal. As reflected in these papers, archaeological science can help to unravel the intangible heritage of past societies by bridging the boundaries between the technicality of making and working glass and the social signification of this material.