Case study: The social networks of client-rulers in the Roman Near East

John the Baptist before Herod Antipas,
Albrecht Dürer 1509. Source: Wikipedia

This week I went to the annual meeting of the UK Classical Association, which was hosted by the University of Nottingham this year. Colleagues Leonardo Gregoratti (Durham) and Eran Almagor (Ben Gurion University of the Negev) organized a session on "the Eastern Client States", where I took part. Client states in this context refer to polities in the Near East, that held a large degree of autonomy and were rued by local princes, but which were part of the Roman Empire or the Parthian Empire. Herod the Great, king of Judea 37-4 BCE and universally infamous due to the infanticide ascribed to him in the Gospel of Matthew, is perhaps the most famous of these rulers. In fact there were many of them, and even if there is a clear tendency towards direct and centralized rule over time, the Roman Empire always remained a patchwork of cities, tribes, and principalities with varying degree of autonomy, although there was never any doubt that the real power was in Rome and later in Constantinople.

The client rulers are one of the cases I am studying, with the aim of better understanding the fabric of Near Eastern society in the Roman period. In time I plan to make a study of them for the whole period of Roman rule in the Near East, but for the presentation in Nottingham I started in an end, and attempted a network analysis of the system in the first century BCE and the first century CE. Below is a short summary of my preliminary ideas and finds. Comments and advice on how I could develop this are greatly appreciated.

I started by plotting 163 members of ruling dynasties in the Near East from 63 BCE (the start of Roman Rule) until 125 CE and the 369 ties of full siblinghood, marriage and descent between them in Excel. The entries were based on Richard Sullivan's invaluable prosopographical articles for the Aufstieg und Niedergang der Römischen Welt, bolstered with information from classical encyclopedias. The resulting spreadsheet was saved in csv-format and easily imported into the open-source graph visualization software Gephi using this great tutorial from University of Wisconsin Green Bay Digital Humanities blog. After some time spent identifying and correcting errors in my database that became evident during the import-process, i got this unprocessed graph (below). It does not immediately make much sense. The thick lines represent connections between individuals sharing more than one tie, in effect people marrying their siblings, an unusual, but not unheard-of practice among royals at the time.

The next step was to find a good way of visualizing the whole network. I used the force atlas 2 algorithm in order to arrange nodes and edges in a pattern where they did not overlap. Then I assigned the different dynasties different colors, based on the dynasties people were borne into (as opposed to those they married into. This I did by assigning different series of node id's to different dynasties in my spreadsheet, for instance all individuals belonging to the Herodian dynasty got an id-numer starting with 3. In this way I was able to easily filter out all members of this dynasty in Gephi. Now the network looked like this:

Here, the network is organized according to dynasty, showing the different connections of marriage, descent and siblinghood for the period from 75 BCE until 150 AD and colored after which dynasty people were born into. On one hand of course this is problematic, because dead and living people are included in the same network, on the other hand it is useful, as dynastic connections were used for claims to legitimacy as well as territory and position, and it helps us see which families were important local players and who were more marginal. In that sense it gives us a more comprehensive picture than the stemma we usually look at when we study dynastic networks.

Then I wanted to see how the network changed over time. The problem with this is that we don't have secure information about when all the people in question actually lived. I've tried to overcome this by assigning them quarter centuries when they were politically active, either as rulers or simply as marriage partners and parents. Some were active in dynastic politics for almost 75 years, others only briefly. By assigning each period a unique value in Gephi and using the software's partition feature I was able to create time-series of the network. I've made a short movie of these (below).

Here individuals have been sorted into overlapping 25-years intervals, according to the periods in which they were active. Some of them were political figures for three quarters of a century, others only briefly The slides show how the different dynasties engaged with each other over time, making it possible to discuss questions of integration, fragmentation and marginalisation. It shows very well, for instance how the Herodian dynasty of Judea emerges as the regional power-broker in the late first century BC, and how Armenia is constant arena of dynastic competition, where different dynasties vie for influence. Dynasties such as Emesa never really becom important, while Commagene and Cappadocia remained in the game, but were marginalized over time.

Next, I used the really useful Geo Layout algorithm developed by Alexis Jacomy in order to arrange my nodes according to geographical position (which I had included in my spreadsheet). Now all nodes belonging to the same dynasty were gathered in one point, and thus indiscernible, but instead the geographical development of the network over time became visible:

In this example we no longer see the individuals, but ties between the different dynastic centres instead. They move slightly because the scale of the network varies over time. In terms of geography, we have three main clusters, centered on Anatolia, Northern Mesopotamia and Judea, with Armenia and Commagene as not only the geographical, but also the main dynastical links between them. Also this allows us to look at interaction across the so-called border between the Parthian and Roman worlds or spheres of influence. Doing this, we see that these networks are geographically very expansive, spanning from Mauretania and Rome in the West, to Ctesiphon in Mesopotamia in the east at their greatest. We also see that the great rivals of the Romans, the Arsacid dynasty, by way of Parthia and Media Atropatene, are active participants in the dynastic networks of the Roman Near East, although they seem to become less important over time.

I had great fun while trying to model the client king system, but I also found it scholarly very rewarding. More on this at a later stage, but network perspectives allow us to move the focus from the imperial center to a multiplicity of peripheral points of view. Each of the 163 individuals in the network were at the centre  of their own world, and approaching them as a social network allows us to appreciate this in a different manner. At this stage this is very much work in progress, and I'll continue to develop the technical as well as the scholarly side of this in months to come.

Thanks to the audience and my co-panelists in Nottingham for a good discussion!

Ancient networks and New Institutional Economics

Some weeks ago, I visited Marburg, Germany, to attend a conference on Ancient Economies and Cultural Identities (2000 BC - AD 500). The common interest of the speakers, who included economists and philosophers as well as the usual crew of philologists, archaeologists and historians was that of New Institutional Eonomics as an analytical approach to the study of the ancient economy.

For much of the 20th century, the field of ancient economy was ridden by repeated controversies about the nature of the subject itself. Did the ancient economy work according to the same rules as the modern economy, e.g. with regard to the role of the market as the most important way of distributing wealth – this position was called formalism or modernism, or were economic relations in the ancient world embedded in social and political contexts, such as gift-giving and tribute – the so-called substantivist or primitivist stance?

The third round of this controversy, following Moses Finley's classic The Ancient Economy, (now available in full text online!)  reached its climax by the 1980s By the time I studied ancient history, in the late 1990s, the debate had grown completely stale. The study of the ancient economy had to a large extent been transformed into a discipline of cultural history, and the insistence on the uniqueness, even exoticism of the ancient world, effectively barred economic historians of other periods from taking an interest in antiquity, and students of the ancient economy from making their field relevant and interesting to scholars dealing with other empirical and chronological settings.

Meanwhile, however, the field of economics had moved forward. While specialists of the ancient world were debating whether ancient people acted rationally in economic respects, economists had long started to realize that modern people frequently don’t. Scholars developing the field of New Institutional Economics investigated how institutions shape economic behavior. The market is certainly an important institution in this respect, but there are also many others. Transaction cost theory and the realization that rationality is bounded – restricted and shaped by lack of information, cultural and social constraints etc. also helped explain how different economic mechanisms can come into play at the same time.

Ancient historians may be slow learners, but as many of us have come to realize with regard to the study of the ancient economy over the last few years, the beauty of New Institutional Economics is that it allows us to treat social, political and economic relations within the same analytical framework. Of course it mattered to people in the past whether goods changed hands as a result of market exchange, gift-giving or robbery, but for the historian, it can be useful to treat the three as complementary institutions regulating economic exchange in the ancient world, thus giving us the opportunity to ask, and try to answer, what this reveals about ancient society, thus giving us the opportunity to write what Manning and Morris calls «Social Science History»: Comparative, testable and methodologically explicit.

How does this link up with networks? Well, Douglass C. North, among the leading figures of New Institutional Economics, suggests that the world should be interpreted by means of the analytical terms of «organizations» and «institutions». By organizations, he describes groups of individuals, working towards a mixture of common and individual goals by partially coordinated behavior. In the modern, developed world there are all kinds of organizations, including sports-clubs, universities, private corporations, NGOs, municipalities and governments. In traditional societies, including the ancient world as well as parts of the world today, there were a lot fewer organizations, and most of those that were in existence were of political nature: Tribes, city-states, kingdoms, empires etc. These (with varying success) specialize in generating revenue for their members, and in containing violence inside the group as well as with other groups. Institutions, North says, are «the rules of the game», the formal and informal patterns of interaction between individuals and groups.

My point of departure for the NeRoNE project was that Network Analysis is great for mapping, visualizing and even measuring interaction, but that when we deal with the ancient world, we also need to think carefully about the nature of the ties that constitute our networks. New Institutional Economics is one way of doing that. Networks might be conceptualized as organizations, the ties between the actors as institutions. On one hand this adds a qualitative dimension to network analysis, on the other hand network analysis is a possible strategy for making New Institutional Economics operational on data from the ancient world.

The Marburg conference featured lots of stimulating papers on how institutional approaches can inform the study of economic interaction in the ancient world. I look forward to the proceedings that are promised in due time.

School visit: research methods in the humanities and social sciences

Yesterday I paid a visit to Bergen Katedralskole, in order to lecture and advise students in their final year of high school on research methods in the humanities and social sciences. My university each year awards the Holberg International Memorial Prize for outstanding research within these disciplines. In connection with that they also organize a research competition for senior high-school students. Bergen Katedralskole has entered two classes this year, and I am their appointed university liaison. Going there was a great chance to meet and talk with the people who will be starting college or university studies this August, and hopefully also convey why research in the humanities and social sciences is fun as well as important. For me, it was also an opportunity to think about some aspects of what we are doing and why we are doing it. 

The humanities and social sciences engage in the study of human life and culture. Their importance should be obvious, nevertheless it still has to be repeatedly emphasized and also justified. Doing research is about creating narratives. Narratives about the human experience, past and present, tell us who we are and where we come from, and in thus shaping identity, they also serve to create groups and draw boundaries between them. History, identity, and culture are continuously invoked in political and public discourse, for better and for worse. An important role of researchers is to create, uphold, question and dismantle these narratives. We do that by doing research, by teaching and by taking part in these discourses. Engaging with the distant past and far off corners of world is equally important as engaging with the present and the close by, not because we learn directly from history, but because it widens our horizon of what it means to be human, and thus allows us to better understand others as well as ourselves. That is certainly fun and useful on a personal level, but also, I think, relevant to society at large. As far as I'm concerned, there is no crisis in the humanities.

That said, those of us who are so fortunate as to make a living from research certainly have an obligation to make what we do available and relevant to the public This is also the idea underlying SAMKUL program of the Research Council of Norway, which has funded the NeRoNE project. "The glory that was Greece and the grandeur that was Rome" of Edgar Allan Poe is hardly a useful narrative of the past for the 21st century. Researching social networks in antiquity gives insights into how traditional societies work, and by better understanding historical dynamics, we also, hopefully, better appreciate how we ended up were we are, and how traditional patterns of interaction continue to influence interaction in many parts of the world, albeit to different degrees. 

As for recommending the students I met yesterday to pursue degrees in the social sciences or in the humanities, I am unapologetic. The competition they are entering now, will give them a chance to see how research is produced, and this will give them a platform for understanding and also evaluating the products of research, so often relied upon by policy-makers and bureaucrats. If they decide to go on to university studies in Old Norse, French literature, ancient history, social anthropology, or any other among the multitude of exciting subjects we can offer, the education they'll receive will enable them better to understand the world and their place in it. Few of them will continue doing research in their professional lives, but their education will train them in amassing, processing and presenting information, and it will make them highly qualified, flexible and independent candidates, able to adjust to a changing labour market for the approximately 45 years they will spend working after studying human culture and society for three to five years. 

Proto-globalisation in the Indian Ocean World and network approaches

Last weekend I attended the concluding conference of the ERC-funded Sealinks project. The Sealinks group, headed by Nicole Boivin of Oxford University, has investigated the early maritime links that connected societies on the Indian Ocean rim, using primarily evidence produced by archaeobotany, zooarchaeology, genetics and linguistics. Many results have already come out, and these shed light on processes going further back in time and having more profound and lasting impact, than those evident from earlier studies based on artefactual, epigraphic and literary evidence.

The conference gathered researchers working with biological and environmental proxies, along with with traditional archaeologists and the odd historian. Indian Ocean trade and navigation, as well as the  early history of globalisation being among my other research interests, I found the conference immensely informative. It struck me, however, that although almost all presenters used the N-word, there was next to no discussion on what a network is, how past networks can be approached, and what insights this might give. This is not intended as criticism of the work presented, which was generally of very high standard. In fact the observation would be valid for most archaeological conferences I've attended, and I've worked with the Indian Ocean for more than ten years myself before starting consciously to think in terms of networks myself. Indian Ocean connectivity, however, is a subject that would readily lend itself to network approaches, and in this post I'd like to share a few thoughts on how different groups of material might have benefitted from being approached from a network perspective.

Networks of people

My own research on Indian Ocean trade is primarily on merchant networks: how they formed, cohered, operated and interrelated. In my paper in Oxford I argued that merchants from the Syrian city of Palmyra engaged with local and regional social networks of power, ideology/religion and commerce, in the process of expanding their own ethnically based network from the Syrian Desert into Mesopotamia, the Persian Gulf, the Red Sea and the Arabian Sea. Our data on merchant networks are of literary, epigraphic and ceramic nature – the Palmyrene network for instance being attested by circa 50 inscriptions recording the presence or activities of Palmyrene groups and individuals in settings certainly or very likely connected with Indian Ocean trade. Similar data would be possible to utilize for other groups. Ingo Strauch and collaborators for instance recently published more than 200 inscriptions in Arabic, Indic, Ethiopic, Aramaic and Greek script from a sanctuary in the cave of Hoq on the island of Socotra. Many of these should be possible to connect with places of origin, religion, language, and script used, reconstructing the network that intersected at the node of Hoq in a manner that would be possible to approach by the toolbox of Social Network Analysis.

Networks of objects

New inscriptions are occasionally still discovered, but in general, the written evidence relevant to ancient Indian Ocean trade is delimited and finite. The archaeological data available from Indian Ocean settings, however, has exploded over the last two decades, following major excavation projects  and better practices of documenting, identifying and publishing finds. In my opinion, there are cases where distribution patterns are not necessarily well suited for network analyses, as the presence of objects does not always reveal how, when and by which routes and agents they moved from point of origin to find-spot. In the case of the Indian Ocean, however, distribution patterns clearly do have potential for network analyses, as distances, topography and climate led to virtually all communication taking place by sea. Network analysis based on distribution patterns of ceramics, beads and glass – goods that can be traced to place of production on stylistic, chemical and petrographic grounds, could clearly reveal directions, bottlenecks and clustering of trade.

Networks of places

Clearly, the same would be the case with settlements. Attempts at modeling relationships between ports and their hinterlands and between ports, based on size, kinds of imports and exports, period of occupation, distance to other centers, season of navigation etc. might help us think about why some places and some regions were important, while others seem to not to have been taking part in long-distance exchange to the same extent.

Networks of genes

Many of the papers in Oxford were on the movement of crops, animals and people, studied by way of genetic material recovered from archaeological sited. Dispersal of genes was in most cases visualized by phylogenetic trees. This is of course also a network analysis, showing genetic connections between the varieties of crops etc. found in different settings. If sufficient numbers of dated examples exist from a sufficient number of sites, I think these would also be good for showing patterns of prehistoric seafaring.

New Connected Past conference next April

My great colleagues in the Connected Past community is hosting a conference in Paris next April. Their 2012-conference in Southampton was a great success, and this is an event that should not be missed!

Blog: archaeological networks

Check out colleague Tom Brughmans' blog on archaeological networks. Tom is PhD-candidate at Southampton University, and has over the last years established himself as a profiled advocate of network approaches to archaeology. Among other things he is part of the team behind the Connected Past conference in Southampton last year, which was a great inspiration for my own project. His blog is a great place for news on publications, projects and conferences as well as reflections on networks in archaeology.