New publication on Palmyra

Together with colleagues Jørgen Christian Meyer and Nils Anfinset I have a new edited book out. Very little networks, but lots of Roman Near East. These are the proceedings of a conference we hosted at the Norwegian Institute in Athens in December 2012 as a part of a research project on Palmyra. It brings together results of international fieldwork and research on the Syrian caravan city until the start of the Syrian civil war. The book can be bought in paper or as e-book from Archaeopress. See their web-site for full details on contents. 

Meanwhile in Bergen...

It's been too long since I updated this blog, which does not, however, mean that we have been idle. Here is a brief report on some of the things that has happened since May and that will take place over the next few months.

In late May I went to Singapore where I organised a panel at the Asian Association of World Historians  together with Japanese colleagues Masaki Mukai, Hisatsugu Kusabu, and Yasuhiru Yokkaichi. The session was called Pax Romana and Pax Mongolica: New Approaches to the Anatomy of Pre‐modern Martitime Networks (session 4.3 in the program) and proceedings will eventually be published in the open access Asian Review of World Histories, pending peer review. The conference gave the opportunity to indulge in one of my other academic interests, namely world/global history, which interestingly looks different from an Asian perspective despite the disciplines aim to transcend old, Eurocentric paradigms of history. For my interest in networks a splendid session was World Maps as Knowledge Aggregators: from Renaissance Italy Fra Mauro to Web Search Engines (session 5.5. in the program) where the panelists discussed renaissance texts and maps as early examples of hypertext, and how modern software can be used to mine them for information.

Summer started with the Sunbelt Conference om Social Network Analysis in Brighton, where I presented on the social networks of so-called client rulers in the Roman Near East (an updated and hopefully improved version of the study I've written about here. This year there was one archaeological session and several on historical networks. Interest in historical and archaeological networks is certainly up only in the two brief years since I attended the Hamburg conference, and the Sunbelt is becoming a great place for thinking about and discussing methodology with people working with other periods and empircal settings, and for engaging with the social sciences in general, a useful exercice for scholars working with distant periods.

Next stop was in Konstanz, where Tom Brughmans had invited me to visit the Network Science group of professor Ulrik Brandes and to give a lecture on a network analysis of ancient Indian Ocean trade based on the Greek merchant handbook known as the Periplus of the Erythraean Sea. In addition to the opportunity to have a critical and constructive discussion of some of my case studies with a group of experts on network analysis and graph visualisation I was introduced to the Visone graph visualisation software, which contains a lot of nice features for historical network analyses, such as animations of time sequences, which will come in very handy for the above study of ruler networks that I need to write out for publication soon.

One of the reasons that this blog has been silent over the summer is that the terrible events in Palmyra, Syria has taken time, attention and energy. I had the privilege of visiting Palmyra every year from 2004-2010, and did my postdoc on a project called Palmyrena: City, Hinterland and Caravan Trade between Orient and Occident (2009-2013). Suddenly and tragically expertise on the Roman Near East became much more relevant than I would ever have wanted it to be, and some of my time and much of my attention over the last months have been directed at trying to get information on what has been going on, and telling anyone who cares to listen what Palmyra is and why Palmyra is important. Some of this can be found under media on the publications and talks page or on my Norwegian language blog. On a more positive note the events of Palmyra prompted me to return to my half-finished book manuscript on the trade of the city. It is now finished and submitted. Depending on publisher and peer reviews I hope soon to be able to reveal how social networks is the key to understanding the rise and fall of the remarkable city in the Syrian Desert.

Håkon has also been busy, presenting his work on the Manichaean community in third century Kellis, Egypt at the Historical Network Research Conference in Lisbon this September. He has some really exciting networks of the economic and religious interaction of this religious minority group, which I hope he'll blog about himself.

Lots of nice things are planned for the next months. I'll be giving two talks on Red Sea/Indian Ocean trade at two different conferences, one on trade in minerals, the other on textiles. In both cases network analysis provides opportunities for integrating archaeological and historical data, and arguably gives a better understanding of the interactive and mutual activity of trade than traditional approaches. In November Professor Nicholas Purcell (Oxford) will visit our research group Ancient History, Culture and Religion. Purcell's work with Peregrine Horden on The Corrupting Sea has been instrumental in the surge of interest in network studies within classical and medieval studies, and I'm looking forward to hear hvis view on where the study of connectivity stands now. There's going to be a NeRoNE project conference in December. I'll post details on that when the abstracts are all in, and last but not least Birgit van der Lans, Groeningen, will come to Bergen for her postdoc on a Niels Stensen Fellowship. Birgit works on Jews and Christian in the Roman Empire, partly from a social network perspective. She will join our research group and also be associated with the NeRoNE project.


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New publications

Ancient West & East 13 / 2014 / Textile trade and Distribution in Antiquity, Kerstin Droß-Krüpe (ed.) 2014

As I got back from fall-break, the print versions of our two latest publications, one article and one book chapter, were on my desk. Call me old-school, but I enjoy holding the book in my hands, and book chapters are really best read in context with the rest of the volume.

Eivind Heldaas Seland (2014) Caravans, Smugglers and Trading Fairs: Organizing Textile Trade on the Syrian Frontier. Pages 83-90 in Kerstin Droß-Krüpe (ed.), Textile Trade and Distribution in Antiquity. Harrassowitz Verlag.

Eivind Heldaas Seland (2014) The  organisation of the Palmyrene caravan trade. Ancient West and East 13, pp. 197-211. doi:10.2143/AWE.13.0.3038738.

As a word of warning to Network Analysis enthusiasts, there is nothing of that in these articles, both, however, address how networks operated, and how we can approach this by means of modern models, in this case New Institutional Economics.

The AWE article is available online, the book chapter unfortunately not. Also, it was not possible to publish these open access. Preprints should appear in Bergen Open Research Archive (BORA) in time (they are not there yet). Meanwhile, drop me a line if your library does not have these and you require an offprint.

From Palmyra to the Euphrates: Tracing trade routes as networks

This post summarizes parts of a paper presented at the Connected Past conference in Paris, April 24 this year, and parts of a paper offered together with my colleague Professor Jørgen Christian Meyer at the ARAM conference in Oxford on July 14.

The challenge we’re dealing with is tracing the ancient caravan route from the city of Palmyra to the Euphrates. This part of the Near East is inaccessible to archaeologists, and has been so for a long time. Most existing research dates back to the 1930s, when Antoine Poidebard and Aurel Stein surveyed the route from the air and on the ground, from the Syrian and Iraqi sides of the border respectively.

The network analysis is only part of the wider case study, which besides publsihed archaeological work also considers GIS modelling, satellite images, ethnographic accounts, travel descriptions, and the physical environment of the Syrian Desert. Pending peer review, the study will be published in a forthcoming volume of the journal ARAM.

Step one of the Network Analysis was to locate all known archaeological sites in the relevant part of the Syrian Desert (below). This was done on basis of archaeological reports as well as British, French, German and Soviet Maps of the region, cross-checked with Google Earth, the Corona Atlas of the Middle East and Bing Maps. These were plotted in Google Earth, and then imported into Arcmap. Still, considering the scarcity of past archaeological work, we had no idea whether there were not also other sites out there, that might equally well have been stations on the trade route.

We decided to approach this by looking at hydrology. If you want to move through the Desert with a caravan, you’ll need to know where to find water. Utilizing 1:100 000 maps imported as overlays into Google Earth we plotted all hydrological features in Google Earth. Imported into ArcGis they look like this (below). Altogether there are 244 of them, wells, springs, cisterns. Can we trust that they were the same in antiquity? To a large extent we think we can. The climate has not changed much. Most wells draw on groundwater and are placed at the bottom of wadis, seasonal watercourses that were the same in antiquity as they are today. Finally, our experience from the area North of Palmyra, where we did survey for four years, is that these wells and cisterns are associated with pre-Islamic pottery, and have thus been in continuous use by the nomadic population.

This, however, still did not enable us to trace the route. In order to do that, we turned to network approaches.

First, I added a 20km buffer to all hydrological features (below). 40 km is a long day’s march for people and camels alike, and wherever two circles intersect, you can reasonably walk or ride from one point to another within a day, if you know your way of course. You see here that the region close to Palmyra has a high density of wells. Also, close to the Euphrates, the availability of water is good. Whereas in the middle, you have stretches of up to 100 kilometer without perennial water sources. This is a strong argument that a caravan route needed to be created and maintained, and this was something that the Palmyrenes needed to deal with in their period, regardless of the actual age of the ruins that early explorers in the Syrian Desert visited.

(The map also shows the routes proposed by Poidebard and Stein as well as the theoretical cost path suggested by Arcmap).

I then wanted to turn this into a network. This I did in Arcmap, by automatically creating lines from all hydrological points to all other hydrological points within 40 kilometers. I then exported all points and lines as spreadsheets, keeping information on geographic location intact. These I imported into the Graph software Gephi, using the Geo-layout algorithm plug in developed by Alexis Jacomy. Below you can see what the result looked like.

I did the same with the archaeological sites identified by earlier scholarship. Here, inspired by Cyprian Broodbank and Anna Collar’s use of Proximal Point Analysis, I added the minimum number of edges needed in order to connect nodes to their closest neighbors on all sides. This, I admit, is probably the weakest point of the analysis, as it involved a certain amount of personal judgment.

I then merged my two networks by combining the spreadsheets. This is the result, with nodes sized according to betweenness centrality. We see very clearly how the areas with good access to water, were connected by places where we find archaeological evidence in the nature of defensive structures or inscriptions, and that these nodes act as gateways, that serve to integrate the network.

Calculating shortest paths proved not to be so useful, because there are so many nodes very close to each other and because this treats minor cisterns in the same manner as large fortified stations and major wells, but the measure of betweenness-centrality gives a very good indication that there are some places you simply need to go if you want to have something to drink on your way from Palmyra to Hit. By the way, the shortest path from Palmyra to Hit is 11, coinciding very with recorded travel times of 10 to 14 days. Indicating that the proximal point approach works fairly well.

So, in conclusion. What did we learn from this, and what did Network approaches contribute with?

In terms of the identifying the trade route, it seems safe to say that Poidebard was correct in Syria and Stein was correct in Iraq. What did we contribute with then. Well, while they followed tracks on the ground, there was no guarantee that there were not other tracks around that they never saw. We have made their conclusion testable, by showing that there simply was no other feasible route if you wanted to go the whole way between Palmyra and Hit in the dry season. In that way the question about the date of the ruins in the desert becomes less important, because whether there were fortifications there or not in the Roman period, the network layout shows that the Palmyrenes needed to pass through this places.