Information extraction from medieval sources and historical network analysis: Late medieval clerical networks in the Repertorium Germanicum

Robert Gramsch-Stehfest, Christian Knüpfer and Clemens Beck

Time and Place: Thursday, 01.07., 10:00–10:20, Room 1
Session: Networking Publications

The paper provides insights into the investigation of the structures and protagonists of the late medieval German church by means of information extraction and social network analysis. The basis of our survey is the Repertorium Germanicum, one of the largest editions of German medieval sources at all.

For quite some time, historians have been discussing the automatic indexing and exploitation of the Repertorium Germanicum using digital methods, see for example Höing and Reimann. Also the potential of a network analytical evaluation of this material was already demonstrated by Schwarz (I and II) and discussed in general by Gramsch (I and II). But so far these techniques have not been tested systematically. Until now, a major obstacle of the investigation of the manifold entanglements between medieval German clerics documented in the Repertorium Germanicum is a very laborious data gathering by hand. We therefore are currently working on a semi-automatic information extraction process for the Repertorium Germanicum on the basis of a knowledge base logically representing the historical information. For a formal and reusable representation of this information an ontology of medieval church and clerical prosopography is needed, which we currently develop together with the Germania Sacra and the German Historical Institute in Rome. This ontology is based on CIDOC-CRM.

In this paper we will show how information extraction methods based on formal ontologies and social network analysis open a very efficient way to model and analyse large networks of hundreds of medieval clerical actors. We will do this in two steps:

In a first step, we will discuss the requirements for a semi-automatic information extraction from the Repertorium Germanicum, the main source for the “curial benefice market” in the 15th century. It consists of many thousands of Regesten deriving from the late medieval Vatican Registers and containing a huge amount of prosopographical data. The registers have a very elaborated regular structure, which is based on the terminology of the late medieval Canon and Roman law. We therefore will show the core of a formal ontology of the institutions and hierarchies of medieval church, the career paths of medieval spiritual elites and their interpersonal relations, which can be used for a digital representation of the prosopographical and other historical information. Based on this core ontology we will also introduce information extraction tools that allow for data harvesting from the Repertorium Germanicum. One example is the the automatical identification of the clerical actors in the Regesten, based on the extraction of their first names, surnames, and their official positions. Together with the ontology these tools will form the basis for the second step – a historical network analysis of the source material.

In this second step we will report on a social network analysis of the money transfers between Germany and the Vatican during the pontificate of Pope Sixtus IV. (1471-84). A social network consist of nodes (individual actors) and edges (relationships or interactions) that connect them. The analysis of such a social net tries to assess the social capital of the actors represented in it. In our case study the nodes were clerics and bank companies, while the edges were financial transactions between them. The analysis of this network proved to be exceptionally good for showing the benefits of our approach. Using the information on the offices of clerics and common abbreviations of the Repertorium Germanicum Regesten that we represented in our ontology, we extracted the relevant information and modelised the financial system as a network in which we found surprising patterns: The main result of this network analysis was not, as one might expect, that only the bank companies played the mayor role in the financial transactions between clerics and the Curia. Another important player was a small group of German clerics (the so called curialists) who worked at the Roman Curia and arbitrated business contacts between Italian bank houses and German petitioners at the Curia. Because of their intermediary services for various persons, noblemen and bank companies, these curialists accumulated a large amount of social capital, which they could use for their own career after their return to Germany. Melchior von Meckau, e.g., who is represented in our network model by a node with an exceptionally high betweeness centrality, many years later became councillor to Emperor Maximilian I, Bishop of Brixen and finally Cardinal. Thus the career of one of the most successful German clerics of the late 15th century casts a shadow in a network structure derived from the text of the Repertorium Germanicum!


  • Gramsch I: Robert Gramsch, Prosopographische Auswertung der päpstlichen Briefregister: Individualbiographien und Klerikernetzwerke im Spätmittelalter, in: R. Berndt (Hg.), „Eure Namen sind im Buch des Lebens geschrieben“. Antike und mittelalterliche Quellen als Grundlage moderner prosopographischer Forschung (Erudiri Sapientia: Studien zum Mittelalter und zu seiner Rezeptionsgeschichte, 11), Münster 2014, S. 167-180.
  • Gramsch II: Robert Gramsch, Zerstörte oder verblasste Muster? Anwendungsfelder mediävistischer Netzwerkforschung und das Quellenproblem, in: M. Düring / U. Eumann u.a. (Hgg.), Handbuch Historische Netzwerkforschung. Grundlagen und Anwendungen (Schriften des Kulturwissenschaftlichen Instituts Essen zur Methodenforschung, 1), Berlin u.a. 2016, S. 85-99.
  • Höing: Hubert Höing, Die Erschließung des Repertorium Germanicum durch EDV- gestützte Indices. Technische Voraussetzungen und Möglichkeiten, QFIAB 71 (1991) S. 310-324.
  • Reimann: Michael Reimann, Neue Erschließungsformen kurialer Quellen: Das Repertorium Germanicum Nikolaus‘ V. und Calixts III. (1447-1458) mit computerunterstützten Indices, Römische Quartalschrift für christliche Alterumskunde und Kirchengeschichte 86 (1991) S. 98-112.
  • Schwarz I: Brigide Schwarz, Klerikerkarrieren und Pfründenmarkt. Perspektiven einer sozialgeschichtlichen Auswertung des Repertorium Germanicum, in: QFIAB 71 (1991), S. 243-265.
  • Schwarz II: Brigide Schwarz, Alle Wege führen über Rom. Eine „Seilschaft“ von Klerikern aus Hannover im späten Mittelalter (1. Folge), in: Hannoversche Geschichtsblätter N.F. 52 (1998), S. 5-87.