Mapping the Documentary Material of Teutonic Prussia
An aggregate map visualizing the origin of about 3,000 documents pertaining to the colonial conquest and administration of medieval Teutonic Prussia during the period 1200-1450. The darker the color, the higher density of documentary production.
The stated aim of this project was “to experiment with digital tools to visualize and analyze the ways that the spatial configuration of Prussia changed over the course of the crusades.” My results to date are promising, although there is a great deal of room to expand and refine my data, and a great many more ways to creatively manipulate it. So far, I have managed to compile a database tracking basic information drawn from about 5,000 published documents relating to the Teutonic Order’s conquest and colonization of Prussia during the thirteenth through fifteenth centuries. I have also begun to visualize this data using GIS software. As the data set grows, so too will the potential for spatial visualization and analysis.
A major goal of the project was to map “imaginary” cartographies (drawn from literary texts) upon “real” geography (aggregated from documentary evidence) in order to see how closely they align. I continue to be interested in bridging the gap between the realm of spatial abstraction and the very real world in which we live our daily lives, and in how each shapes or influences the other. So far, this goal remains elusive. Thinking about the potential of digital tools, topic modeling could eventually prove useful in teasing out the verbal portmanteaus of spatial imagination in texts like chronicles and hagiography. Of course, would be an immense and complex project of its own—there is the daunting methodological challenge of working across medieval languages, let alone the tremendous effort needed to digitize untranslated medieval texts. Other methods are not as far out of reach. With a relational database, I have the power to add more abstract data—perhaps the occurrences of words like “wilderness” or “danger” in association with places compiled and geocoded in the database—to the more mundane documentary data which has formed its basis. Either way, the results of the project will continue to fuel (and be fueled by) a developing dissertation on the topic of understanding space on its continuum of abstract and physical manifestation.
The map at the top of this page is one example of how I have begun to visualize the data compiled in my database. As its caption explains, it depicts the origins of the roughly 5,000 published documents that currently make up the database’s contents. Some places produced more documents than other places. Rome and its surrounding towns—sites of Tuscan papal retreats, in fact—were clearly a hotbed for producing documents which made their way to the Teutonic Order’s Prussian outposts; other places like London had connections to the Order, but to a lesser degree. This particular map includes places that produced as few as five of the 5,000 documents (0.1%) to as many as 520 (10%).
It is also the purest representation of the spatial data I have collected: simply the origins of the documents. It is clear how this data could be useful for historians interested in the aggregate documentary administration of Teutonic Prussia. Less clear, however, is what a map like this can really say about “space.” Tackling this dilemma requires some imagination. In the medieval world, documentary production acts as a proxy for a wide variety of activity: administration, communication, trade, correspondence, travel. The kinetics and networks of space are inherent in the production and conveyance of documents.
Much work lies ahead in developing and unearthing these underlying features. The map above, however, is a good start in outlining the nodes and contours of power, information, and wealth in Teutonic Prussia.
Visualizing Change Over Time
Still, what we have so far aggregates data from over 250 years. Breaking this time down into smaller intervals gives a sense of how these networks changed and developed. Below are thirteen maps, each tracking the same information, but in chunks of fifteen years starting in 1215.
Before presenting these maps, there are two caveats:
1) There is a chunk of almost forty years (1345-1382) missing from the digital source of the documents compiled in the database. This lacuna doubtless skews all the results presented here, and the need for a solution is becoming increasingly urgent.
2) A similar problem applies to documents from the fifteenth century, which were very inconsistently digitized and thus very difficult to datamine.
Overall, the data presented is more consistent and coherent before the year 1345.
Serializing the data makes it possible to observe several obvious and relatively unsurprising trends. (1) There is a steady growth in Prussia itself, with places like Marienburg, Thorn, and Königsberg becoming the major hubs of activity. (2) The papacy (located in central Italy until 1309, then in Avignon until 1379 before returning to Rome) begins as the main documentary hub, and gradually becomes eclipsed by centers in Prussia; still, it always remains a central hub in the network. (3) In the late-fourteenth century, there is greater contact with the surrounding Baltic, and a maritime network is in full bloom by 1400; this in part reflects the growing activity of Hanseatic traders in the late-fourteenth century into the fifteenth.
Visualizing the data across time does not hold any surprises. In fact, the greatest surprise is probably the relative consistency in the development of the network of communication, administration, and exchange. In other words, places that become important early on (Rome, Marienburg) generally remain the most important, even if they gradually bring lesser satellites into their orbit, and contact with medium-significance places like Vienna, Prague, and Cologne remains fairly steady. It is unclear whether these trends will hold under greater scrutiny. It is also unclear to what degree they are skewed by the underlying choices of the editors who compiled and published the documents. A set of Teutonic documents from Iberia, for instance, could illuminate a corner of the map which remains completely dark for the entire period.
Organizing time scale in intervals of years is the typical knee-jerk reaction of most historians. But even my simple data has more creative ways to visualize space across time. Since most documents include a month, for example, they can be organized seasonally: summer (May-September) and winter (November-April). The results for the thirteenth century are displayed below.
The results of these maps are actually quite disappointing. I hoped that there might be obvious patterns distinguishing winter- and summer-production, which could suggest differences in travel routes and so on. These two maps look almost identical, however. I do have a suspicion that I may not be using GIS properly to visualize this data. Otherwise, another explanation is that the date that documents record is typically the date of their production, not reception. So while these maps suggest there is no difference in where documents originate from in summer and winter months, there could still well be differences in their transmission. Either way, I want to continue experimenting with seasonality as a temporal dimension of space.
Geography and Space
One short-term goal in continuing this project is to make better use of baselayers to see how my data maps onto different representations of the same space. A simple example is depicted below:
The above map simply uses a satellite baselayer to show how the major centers of Teutonic power in Prussia (and their neighbors along the Baltic Sea) map onto the topography. Perhaps the most evident pattern to observe here is that the locations of higher production capacity are located along rivers and coasts. This makes sense, since the majority of communication and transportation was along the waterways. However, it is worth noting that the relative importance here is determined by the role of each location in networks of communication. The smaller, “less-important” nodes inland from the rivers were often key strategic points, even if the data at hand does not reflect this particular role.
Visualizing People Across Space
A final example of my results so far traces the people inherent in communication networks. Compiling the prosopographic section of the database has been both time-consuming and challenging, and I have only parsed the thirteenth-century documents for their creators. Still, the resulting data makes an interesting map.
It reveals that a huge amount of the thirteenth-century documentary production—in fact, virtually all of it south of the Alps—comes from one source: the pope. Furthermore, all of the documents coming from outside of Prussia itself originate from sources at the top of their respective hierarchies: popes, archbishops, cardinals, grandmasters, and kings. Within Prussia, there is a broader array of people creating documents: Abbots, bishops, commanders, and others who do not make it onto the map (townspeople, settlers, priests, deacons, and so on). It is also interesting to note a geographic and social correlation. The purple dots designating various ranks in the Teutonic Order are at the core of the developing Teutonic landholdings, while the green dots indicate dukes are on the edges. This nicely illustrates the tense division of land between the Teutonic newcomers and the Polish dukes who had long been in conflict with the native Prussians. In a simple way, this map suggests the power of GIS to reveal patterns about people as well as places.