By Carl H. Nightingale*, University of Buffalo

The Archive Box is a series featuring global urban historians reflecting on their archival experience, and on the practical and theoretical challenges they faced while working with a variety of archives across the world.

How does one write a continent and millennia-spanning “biography of an Urban Planet,” while maintaining a strong grasp of the different sources which allow us to tell such story? Carl H. Nightingale has taken on this arduous task, and reflects here on the necessary interplay between primary, secondary, and tertiary archives to push global urban history forward at a moment of political and environmental crisis.

Over the past four years, I have been writing a book called Earthopolis: A Biography of Our Urban Planet (Cambridge University Press, June 2022). It explores the idea that cities amplify all of the following: humans’ capacity to act, the scope of the human habitat more generally, the severity of human impact, and the consequences of human acts, habitats, and impacts in space and time. The book thus asks urban historians to stretch and remap “the urban” geographically and historically.

Cities, as we know well, draw on many types of non-city spaces for energy, food, water, raw materials, and building materials. William Cronon notably explored this aspect of urbanity in Nature’s Metropolis, tracing Chicago’s elemental dependence on inflows of city-making things from its vast North American hinterlands. Because hinterlands make cities possible, it is useful to call such spaces urban even though they are not cities. More challengingly, we must find ways to reckon with the fact that their location outside cities and inside the urban varies in complex ways, and ultimately (I think) to unmeasurable degrees over time. I also think it is worthwhile to consider the geography of what we might call “meta-hinterlands” – the types of geophysical spaces that provided urban hinterlands with their principle source of city-creating energy. Accordingly, Earthopolis is divided into three parts – “Cities of the Rivers,” “Cities of the World Ocean,” and “Cities of Hydrocarbon.”

Earthopolis also pushes us to think more about urban outflows. How do we map the space occupied by the amplification of acts, habitats, impacts, and consequences that arise from concentrating larger amounts of people, structures, and natural resources in cities? Such urban forelands come into being as we compound energy from the Sun and Earth into human power, in the form of institutions, networks, and mass movements that cannot exist without enlarged concentrated habitats. When such city-dependent deployments of human power expand in scope, historians have named the spaces they occupy by many useful terms: states, empires, world systems, systems of global “connections,” global capitalism, world religions, global consumer cultures, “anthromes,” pollution-sheds, or “bioeconomic regimes.”  For global urban historians, it is important to emphasize the essential if not sufficient role cities play in the generation of such larger spaces (the causation always simultaneously goes in reverse too – urban outflows transform cities). When urban forelands – and the urban hinterlands that make them possible – take on planetary scope, as they certainly did at different times, it is useful to think of them as indications of the historical existence of an “Urban Planet.”

The usefulness of “Urban Planet” depends on paradox. One of the most important is to recall that, as “singular” as an Urban Planet may be – ours is the only one we know of in the universe – the “urban” is nearly infinitely diverse, not to mention obscenely unequal. Imagining histories of what became a “plural singularity” is challenging. No one narrative – and that includes the particular narrative I offer in Earthopolis – will ever suffice. It does help to remind ourselves of the fact that cities first came into being, largely independently, in dozens of mostly independent regions over the course of the first five-and a half millennia of global urban history. Such foundational guarantees of urban diversity have only propelled further diversification – and inequalities – in “the urban,” even as the urban extended (and often retreated) in scope. On top of that, historians willing to tackle the enlarged “urban” will also need to do a lot of work to map the sheer diversity of urban hinterlands, forelands, and the often deeply fragmented inside-outside spaces where they overlap and bring each other into being. Along the way, though, cities, the largest and most concentrated of all human habitats, fostered their own internal diversification, often widening differences between them as well. To imagine the historical development of this plural singularity, urban historians’ foundational professional obligation to our primary archives – informed by archaeologists’ attention to their digs – should predispose us to an ongoing rethinking of the urban that relies simultaneously on epistemologies of “splitting” and “lumping.”

On that point, Ayan, your invitation to an interview for “Archive Box” made me a bit nervous, because Earthopolis involved very little primary archival research. As I thought about it, though, my experience writing the book does suggest a few observations about the relationship of primary archives to the secondary archive that urban historians have produced over the past hundred years or so – and from there to what we might call a “tertiary archive,” that is, the many debates unfolding in the field of urban theory.

Start with the primary archive: after all, it is the starting point for the whole field of urban history. When urban history took fuel from the social history revolution in the 1960s, it also took on its parent field’s deeper, thicker, more diverse, more critical, more deconstructive, “against-the grain” readings of archival evidence. That work has allowed us to resplendently reconstruct the past life of so many cities. The primary archive is also the starting point for our careers: we must immerse ourselves in the complexity – even cacophony – contained in every box, or old diary, or photograph, or statistical digest, or folk song or oral interview – and distill useful interpretations of what we find. The primary archive, we learn correctly, is the primary location for “new” discoveries and interpretations crucial to pushing the field – and our careers – forward.

The primary archive is also the starting point for good global urban history. Getting to “the intersection of global history and urban history” requires us to interpret primary archives not only for the dense textures that are foundational to urban life, but also “against-scale.” That can mean reading leavings of the past that otherwise immerse us ever deeper into a locality with an eye to teasing out their comparative, regional, national, hemispheric, global, and even planetary implications, along the way revalidating the history of even the smallest of urban spaces. Working on primary archives pertaining to multiple cities is another way to build larger-scale perspectives on primary materials we are interpreting. Increasing numbers of urban historians have taken this route, despite the difficulties. Another route from the primary to the global urban starts with archives on national or international matters and burrows back to localities. Look at the research of Global Urban History Project colleagues and you will discover work that followed all of these pathways, with fantastic results. One big accomplishment is to expand our knowledge of cities outside Europe and North America, where, after all, most of the fastest growing cities of the world now exist. As our primary research expands, so too does the secondary archive that represents our field’s contribution to the store of human knowledge.

We should not let our secondary archive sit on its lovely laurels, though. Far from a static monument, it can play a huge role further expanding the insight it contains. All of us read plenty of our colleagues’ work to frame questions, make comparisons, and extend the contexts and scope of our own inquiries. The secondary archive, the distillations of materials from countless primary archives, is enormous beyond telling. Keeping up with all of the annual output in the field alone is impossible for any single scholar. Yet, when Cambridge University Press asked me to propose a narrative of “global urban history” as a whole, the only way forward was to dig as deeply and widely as I could in the secondary archive. Luckily, I was already doing a lot of that for a course I was teaching at the University at Buffalo. Indeed, originally, I saw the project as a chance to write a semester’s worth of very good lectures, a task that always gives us an excuse to read the work of colleagues we may have missed in the rush of new books and articles (this format remains – the book has 25 chapters more or less befitting a 13-14 week semester). I made much use of GUHP’s “Meet Other Members” webpage while writing too, because it is a very good guide to this secondary archive. Finally, I took the assignment as a chance to dabble in archaeology, some global and environmental history, and even in the work of natural scientists interested in climate change and the many other contemporary human-created planetary predicaments they hope to officially rename as the “Anthropocene Epoch.” When GUHP colleagues suggested these topics for our “Dream Conversations,” I was quick to jump into those debates as well.

As I dug deeper into what became Earthopolis, it became clear that the secondary archive could inspire new directions on its own. As you will see, the book proposes a few new ways to solve the old problem of how to define “a city,” while also explaining how cities’ very design prevents us from doing that with any finality. It also extensively explores uses for the the concept “Our Urban Planet, ”a phrase I borrowed– selectively – from the “tertiary archive” of urban theory. I reconceived the idea that cities are creations and creators of planetary space in terms of “deep” historical phenomena such as geo-solar energy, and the role of differently designed spaces in amplifying the exercise human political power. Meanwhile, I hope the particular narrative I propose – again, only one among infinite possible ways of telling the stories of cities on Earth – makes a contribution to the ongoing task of pulling urban history off its axes centered on the  modern-era and the, Global North.

That brings us to the tertiary archive, the vast realm of urban theory. Global urban history’s relationship to theory is vexed. Though urban historians use theory selectively, we play almost no role in producing it, and urban theorists almost never read much history. We have mostly thrown up our hands at this situation – after all, the sheer volume of work in urban history and urban theory is a major deterrent to cross-pollination, and the two fields’ languages, stylistic conventions, basic methodologies, and, most importantly, their associational structures can be difficult to integrate.

Urban historians, and global urban historians in particular, must pay more attention to the tertiary archive. “Vexed things” are notorious for generating new insights of their own. Plus, there are signs that things are on the cusp of changing. Urban historians are reviving fruitful discussions of “the urban” on our own, in panels at several conferences, and notably in GUHP’s “Dream Conversation” on “Theory Of, For, and By Urban Historians.” Meanwhile theorists like Ananya Roy and Christian Schmid have often gestured to something they call “the historical” as a way of solving problems of their own. GUHP has welcomed a few theorists in its ranks, and the historical geographers amongst us provide useful bridges across the many divides in urban studies, as did Richard Harris in his Cambridge Element How Cities Matter.

As Professor Harris suggests, the way forward is daunting: to start publishing theory ourselves. The ferocious theoretical debate on “planetary urbanization” is an obvious entry point for global urban historians, since it lurks so obviously at our own “intellectual crossroads,” but it is not the only way in. Earthopolis is not a work of theory, but it contains theoretical implications for the tertiary archive that I hope to elaborate in print soon. The paradoxes contained within “Urban Planet” – small and large, inside and outside, singularity and plurality, humanity and diversity, creation and destruction, continuity and disruption – are also useful for exploration of our primary and secondary archives too. I think it expands our capacity to tell stories about cities and “the urban.” “The biography” of “Our Urban Planet” is polyrhythmic, a field of nearly infinite possible retellings from the infinity of points of view that make up the space it occupies in time.

The ultimate proof of “Urban Planet’s” usefulness, though, will come from its success in prompting urban historians to contemplate the role our work can play in response to the multiple “Anthropocenic” predicaments of our own time. Cities – and “the urban” – after all, came into being as human alterations of the relationship of Earth and Sun. Surely, professionals who produce knowledge about the urban past need to step up like the rest of us, as all of us contend with the looming planetary consequences.

*as told to Ayan Meer.

Carl Nightingale has taught urban history and world history for twenty-five years as a Professor at the University at Buffalo, the University of Wisconsin-Milwaukee, and the University of Massachusetts. He is Coordinator of the Global Urban History Project. His book Segregation: A Global History of Divided Cities (2012) was co-winner of the Jerry Bentley Prize from the World History Association.