Social network analysis (SNA) has been gathering momentum in medieval studies for several decades, but edited volumes that systematically survey its application across such a wide range of sources, periods, and methodological questions remain rare. This collection, assembled by Matthew Hammond, fills that gap with ambition and considerable success. Fifteen chapters, organized into five thematic parts, carry the reader from foundational methodology to specific case studies in Scotland, Flanders, Iceland, and Germany, with a preface by Johannes Preiser-Kapeller that frames the broader stakes of the enterprise. The result is a serious and valuable reference point for historians wishing to understand what formal network methods can do with medieval evidence.
Scope and Structure
Hammond opens with an introductory chapter and a methodological survey (Chapter 1) that walks non-specialist readers through the core vocabulary of SNA—centrality measures, ego-networks, density, homophily, community detection, bipartite graphs—illustrated with examples drawn from Scottish royal charters. The discussion is clearly pitched and the decision to anchor abstract concepts in a familiar historical dataset is well judged. A worked table of centrality scores for witnesses of Robert I’s charters gives the reader an immediate sense of what the numbers mean in historical terms: that Walter Stewart’s high betweenness score reflects his role as a connector between otherwise separate clusters of the royal court, not merely his prominence. Ego-network diagrams of Master Merlin of Glasgow, whose connections span ecclesiastical, noble, and royal milieus, are used to illustrate how an individual’s relational position can be recovered from documentary evidence.
The introduction gestures towards expanding SNA to “Mediterranean and Byzantine zones,” but this aspiration sits uneasily with the volume’s actual contents and is never backed by citations. Lugli’s [1] study of trading networks in fourteenth- and fifteenth-century Italy and Preiser-Kapeller’s [2] work on maritime Asia Minor as a religious contact zone would have been obvious candidates to substantiate the claim that such research already exists in robust form.
The Historiography of a Method
The bibliometric chapter is one of the most original contributions in the volume. Rather than offering a narrative survey of the field, Ruffini-Ronzani and de Valeriola construct a citation network of historical network analysis scholarship since the 1960s and submit it to the same formal analysis the volume advocates for medieval evidence. The result is a four-era periodisation of the field’s development, from early sociological borrowings through the emergence of dedicated historical network analysis in the 1990s to the current moment of disciplinary consolidation. By calculating betweenness centrality scores for works within the citation network, the authors identify “knowledge intermediaries”—texts that served as methodological bridges between communities of scholars who would not otherwise have encountered one another. Padgett and Ansell’s [3] study of the Medici emerges as the single most persistent hub, which will surprise no one familiar with the field, but the quantitative demonstration of that influence adds texture to a familiar story, and several of the other high-betweenness texts are more unexpected.
The chapter’s acknowledged weakness is its bias in matters of source selection and languages, which leaves Italian, Spanish, and German contributions largely invisible in the resulting network. This is more than a caveat: it means that works such as Burkhardt’s [4] theoretical framework for identifying genuine networks in pre-modern towns, or Soldani’s [5] research on foreign merchants in late medieval Barcelona, which engages directly with methodological objections to applying network theory to medieval evidence, are absent from a historiography that claims to map the field. Ryabova’s [6] study of the Soranzo trading firm, which explicitly compares whole-network and egocentric approaches and addresses data completeness problems in medieval commercial sources, represents exactly the kind of methodological debate the chapter should have registered. The bias is an irony worth dwelling on in a volume that repeatedly calls for a Mediterranean turn.
Gramsch-Stehfest’s contribution on “big data” in medieval history is the most philosophically ambitious piece in Part One. Drawing on his own sustained work with the Repertorium Germanicum—a vast calendar of German benefice-holders in the papal curia—he reflects seriously on when quantitative network reconstruction becomes historically meaningful rather than merely technically impressive. The chapter is partly a methodological proposal and partly a demonstration: Gramsch-Stehfest shows that the ranking of key financial actors in the Roman curia remained stable when his dataset was expanded by 80 percent, a robustness test that provides genuine grounds for confidence in network findings derived from incomplete medieval sources. The figure of Melchior von Meckau—flagged as a high-betweenness broker in the smaller study and subsequently confirmed as historically significant by traditional archival research—illustrates elegantly how network metrics can generate productive hypotheses rather than merely ratifying existing knowledge. Engagement with Weissen’s [7] study of Florentine banks in Germany, which grapples with the same challenge of reconstructing commercial networks from fragmentary German archival evidence, would have provided a useful parallel case.
Medieval Sources under the Network Lens
Part Two, the largest section of the volume, applies SNA to a varied range of narrative and documentary sources. MacCarron’s chapter on Bede’s Historia Ecclesiastica Gentis Anglorum is among the most carefully executed. Working from a twelve-category relational typology—distinguishing kinship, friendship, fosterage, religious mentorship, political alliance, and several more—MacCarron codes every named interaction in the text and constructs a network that can be interrogated for structural patterns invisible to close reading alone. Wilfrid emerges as the most central figure by betweenness centrality, a result that cuts against Bede’s editorial presentation of the controversial bishop as peripheral to the main arc of English Christianization. More remarkable is the finding about women: though present in far smaller numbers, Hild of Whitby, Eanflaed, and several other royal women achieve betweenness scores disproportionate to their frequency, suggesting that their structural role as connectors between otherwise separated regions and communities was greater than a simple count of their appearances would indicate. The chapter is appropriately cautious about the gap between narrative representation and historical reality, and the comparison with Balzaretti’s [8] work on Theodelinda’s role in Lombard political networks would have sharpened the methodological stakes of that distinction.
Carson Koepke’s chapter on Latin hagiography in early medieval England pursues an entirely different kind of network: not the social relationships within a text but the manuscript relationships between texts, traced through shared contents. By mapping which manuscripts containing the Eustace legend (BHL 2760) share saints’ lives with other manuscripts, Koepke constructs bipartite networks that allow him to infer the probable contours of a Continental legendary circulating in tenth-century England. The argument—that the topology of this manuscript network can help explain which saints Ælfric chose to translate into Old English—is inventive and the methodology is explained with admirable clarity.
Ian Styler’s chapter on the Liber Eliensis and Cassidy Croci’s analysis of Landndmabók both grapple with the difficulties of applying SNA to composite or politically shaped texts. Styler codes the interactions across all three books of the Liber Eliensis and finds significant structural differences between them: the ratio of interactions to individuals is markedly higher in Book 1, and secular figures such as the ealdormen Æthelwine and Byrhtnoth emerge as underappreciated network hubs whose importance traditional scholarship focused on abbots and bishops has tended to obscure. The observation that these structural differences may point toward multiple authorship is intriguing, if yet undemonstrated. Croci’s analysis of the Icelandic settlement text is the theoretically richest contribution in this section. By showing that Bjørn buna—the probable ancestor of the thirteenth-century Sturlungar who compiled the main recensions of Landndmabók—achieves a degree of network centrality that far exceeds what any independent settlement-period evidence could justify, Croci demonstrates with unusual precision how SNA can expose the political logic embedded in genealogical sources. The chapter’s comparative framework would have been strengthened by engagement with Carvajal de la Vega’s [9] work on kinship and commercial networks in the Crown of Castile, which examines analogous processes of genealogical construction serving contemporary legitimation purposes.
Ecclesiastics, Nobles, and Dissenters
Part Three moves to documentary evidence and contains some of the volume’s most varied methodological experiments. Ruffini-Ronzani’s chapter on the diocese of Cambrai-Arras reconstructs the social network of the Gregorian reform movement during the Investiture Controversy of 1092-1112 by combining charter witness lists with narrative sources, most notably the chronicle of Galbert of Bruges. The chapter raises genuinely important methodological questions about mixing source types: witness lists and narrative accounts capture different kinds of social visibility, and the network that emerges from combining them may not be straightforwardly comparable to one built from either alone. The analysis would have benefited from engagement with Lemercier’s [10] discussion of how pre-modern relationship choices were structurally constrained by family, lordship, and locality.
Laurent Nabias’s chapter on the nobility of the Île-de-France between 1180 and 1437 is the volume’s most prosopographically ambitious contribution. Working from a relational database of over fifteen hundred nobles, Nabias tracks how aristocratic families navigated the successive crises of the Capetian and Valois periods through marriage strategies, factional alignment, and circulation between princely households. The use of bipartite network projection to move between individual nobles and the courts they served—so that two nobles become connected by virtue of serving the same prince, and two princes by virtue of attracting the same noble—is methodologically innovative and opens genuinely new perspectives on patterns of clientelism.
The chapter by Välimäki and Zbiral on late medieval German Waldensians is one of the most compelling in the volume, not least because of the unusual richness of its source base. The inquisition protocols of Peter Zwicker—depositions taken at Stettin in 1392-94 from around 195 surviving witnesses, out of an estimated 455 interrogated—provide an exceptionally detailed record of social interactions within a persecuted community. The authors test a series of hypotheses about the structure of Waldensian networks: whether itinerant religious specialists (the ministers) served as the principal integrative nodes, whether kinship ties were the primary basis of association, and whether residential proximity drove network density. The finding that gender was not a significant predictor of network centrality—women and men occupied structurally equivalent positions in ways that differ strikingly from Cathar networks in Languedoc—is the chapter’s most arresting result and opens comparative questions that the volume does not pursue. Renterghem’s [11] work on the Baghdad Hanbalite network, which found that minority religious communities could exhibit surprisingly decentralized and internally integrated structures, would have offered useful comparative framing.
Gramsch-Stehfest and Beck’s chapter on German clerical career patterns is the most technically innovative contribution in Part Three. Developing an automated parsing grammar (ANTLR) to extract structured data from the dense abbreviations of the Repertorium Germanicum, the authors reconstruct individual benefice itineraries for hundreds of Erfurt-trained lawyers and superimpose them to reveal regional mobility corridors. The visualizations are striking: one can see how clerical careers funneled through particular dioceses that served as nodal hubs connecting the German east to the more richly endowed benefice landscapes of the Rhine.
Temporality and Methodology
Part Four addresses the challenge that most troubles historical network analysis: how to handle change over time. Isabelle Rosé’s chapter takes a biographical approach, using Odo of Cluny (c. 879-942) and Queen Emma of France (c. 890-934) as paired case studies for what she calls the “networked life-course”—a method that tracks how an individual’s relational position shifted year by year as connections were formed, dissolved, and reactivated. The chapter engages seriously with Bourdieu’s critique of biographical narration as illusion and with the theoretical challenges of preserving individual agency within a structural analysis. The paired cases are well chosen: Odo’s network centered on monastic reform connections radiating outward from Cluny, while Emma’s was built through the itinerant royal court and its documentary traces in charters.
Hammond’s own chapter on change over time in Scottish royal charter co-witnessing networks is the most technically sustained contribution in the volume. Using the People of Medieval Scotland prosopographical database, Hammond constructs co-witnessing networks for each regnal year from David I (1124) to Robert II (1371)—nearly 250 years of evidence—and tracks how network density, the size of the dominant component, and the eigenvector centrality of key individuals shift in response to political events: minorities, succession crises, the Wars of Independence, and the gradual transformation of the itinerant household into a more bureaucratic institution. The chapter demonstrates that network density in the Scottish royal court was consistently higher under kings who exercised strong personal authority, and that moments of political fragmentation left clear structural traces in the co-witnessing record. Balard’s [12] comparative work on Genoese notarial practice—which shows that witness selection was shaped by the importance of the act and the social status of the parties—and Rovere’s [13] work on scribal hierarchies in the Genoese chancery would have helped contextualize whether the Scottish patterns are specific to that kingdom or reflect broader tendencies in Latin European documentary culture.
Testing the Method
Part Five subjects the methodology to two particularly demanding tests. Joe Chick’s chapter on Reading between 1350 and 1600 asks a deceptively simple question: did the town’s political elite constitute a genuinely self-selecting social network, or was its apparent cohesion an artefact of the formal requirements of governance? Using join-count homophily analysis applied to conveyancing records, debt instruments, and testamentary evidence, Chick finds that political elites—those who served as mayor or MP—show strong in-group homophily, while economic elites, defined by wealth at death, do not. This divergence, sustained across the period from the late medieval borough through the Dissolution of Reading Abbey in 1539 and into the Elizabethan town, suggests that political participation was a more reliable marker of social clustering than wealth, and that the dissolution of the monastic landlord produced less structural disruption to the town’s social networks than might be expected. The advocacy for join-count analysis as a technique accessible to historians without advanced statistical training is a genuine service. Burkhardt’s [4] theoretical criteria for identifying networks in pre-modern societies would have supplied stronger conceptual grounding, and Muldrew’s [14] work on credit and social value in early modern England would have deepened the contextual reading of Reading’s social structure.
Sébastien de Valeriola closes the volume with a comparative analysis of personal guaranteed networks in Ypres, Tournai, and Douai across the thirteenth and early fourteenth centuries. The three cities operated under different gracious jurisdictions—different institutional frameworks governing debt acknowledgement and suretyship—and de Valeriola uses the resulting variations in documentary form to test whether institutional context shaped network structure. By extracting debtor, creditor, and guarantor relationships from thousands of debt records using semi-automated text mining, he constructs guarantee networks for each city and compares their topology. The finding that the shift from explicit to implicit suretyship in Tournai—in which the guarantor’s role ceases to be named separately in the act—coincides with a structural transformation in how credit risk was distributed across the network is the chapter’s central argument, and it is persuasively made. The Mediterranean comparative literature—Piergiovanni [15] on credit in Genoese law, Spagnesi [16] on medieval guarantee mechanisms, Luzzatto [17] on risk-sharing in Venetian commerce—would have contextualized these northern findings within the broader European transformation of credit instruments, while Mueller [18] on bank loans to the Venetian state and most importantly Kittell [19] on the direct connection between Genoa and Douai though maritime networks represent a body of scholarship on medieval credit practice that the chapter passes over.
Conclusions
The volume’s strengths are considerable. The range of sources covered—narrative hagiography, saga literature, charter witness lists, inquisition depositions, benefice registers, urban debt records—demonstrates convincingly that SNA can be adapted to almost any relational evidence that survives from the medieval period. The willingness of contributors to reflect carefully on the limitations of their own methods, to distinguish network patterns that correspond to historical realities from those that may be artefacts of source survival or authorial shaping, is one of the volume’s most reassuring qualities. The five parts are coherently organized, and the progression from methodological introduction through source-specific applications to explicit testing of the approach gives the volume a satisfying intellectual arc.
Two weaknesses recur with enough consistency to register as structural problems. The first is geographic and bibliographic. The Mediterranean and Byzantine worlds appear in Hammond’s preface and introduction as a desideratum, but are largely absent from the case studies, and the volume’s bibliographies reflect this imbalance: a substantial methodological literature in Italian, Spanish, and German goes consistently uncited. The irony is pointed: individual chapters call for a Mediterranean turn while failing to engage with the scholarship that has already begun to supply it. The second weakness is the absence of dialogue with other time periods where SNA maybe more accepted and used or with other disciplines—particularly economy and sociology—which make use of statistical analysis in different ways and profit from SNA. In the desire to show how far medieval studies have improved on these methods, it is forgotten to see what others down the aisle are doing and can add to our work.
Social Network Analysis and Medieval History is a serious and stimulating collection that will serve anyone working at the intersection of digital humanities and medieval studies. It is also an accessible and challenging introduction for historians considering formal network methods for the first time.
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Notes:
1. Emanuele Lugli, “Linking the Mediterranean: The Construction of Trading Networks in 14th and 15th-Century Italy,” in The Globalization of Renaissance Art: A Critical Review, ed. Daniel Savoy, Studies in Intellectual History, 274 (Leiden: Brill, 2017), 158-185.
2. Johannes Preiser-Kapeller, “Liquid Frontiers: A Relational Analysis of Maritime Asia Minor as a Religious Contact Zone in the 13th-15th Century,” in Islam and Christianity in Medieval Anatolia, eds. A.C.S Peacock, Bruno De Nicola, and Sara Nur Yılmız (London: Routledge, 2016), 117-146.
3. John F. Padgett, and Christopher K. Ansell, “Robust Action and the Rise of the Medici, 1400-1434,”American Journal of Sociology 98, no. 6 (1993): 1259-1319.
4. Mike Burkhardt, “Networks as Social Structures in Late Medieval and Early Modern Towns: A Theoretical Approach to Historical Network Analysis,” in Commercial Networks and European Cities, 1400-1800, eds. Andrea Caracausi and Christof Jeggle (London: Pickering & Chatto, 2014), 13–43.
5. Maria Elisa Soldani, "Tra reti internazionali e spazio urbano. Forme mercantili di comunicazione, solidarietà e gestione degli affari nel Mediterraneo occidentale bassomedievale," in Espaces et Réseaux en Méditerranée VIe-XVIe siècle I: La configuration des réseaux, eds. Damien Coulon, Christophe Picard, and Dominique Valérian (Saint-Denis: Éditions Bouchène, 2007), 81-110.
6. Maria Ryabova, “The Venetian Trading Firm of the Soranzo Brothers and Its Agents (1406-1434),” inReti marittime come fattori dell’integrazione europea = Maritime networks as a factor in European integration, ed. Giampiero Nigro, Atti delle “Settimane di Studi” e altri Convegni, 50 (Florence: Università di Firenze, 2019), 229-253.
7. Kurt Weissen, Florentine Banks in Germany: The Market Strategies of the Alberti, Medici, and Spinelli, 1400-1475, trans. Kristina Mundall and Nigel Stephenson (Heidelberg: Heidelberg University Publishing, 2024).
8. Ross Balzaretti, “Theodelinda, ‘Most Glorious Queen’: Gender and Power in Lombard Italy,” The Medieval History Journal 2, no. 2 (1999): 183-207.
9. David Carvajal de la Vega, “Merchant Networks in the Cities of the Crown of Castile,” in Commercial Networks and European Cities, 1400-1800, eds. Andrea Caracausi and Christof Jeggle (London: Pickering & Chatto, 2014), 117-134.
10. Claire Lemercier, “Formal Network Methods in History: Why and How?” in Social Networks, Political Institutions, and Rural Societies, ed. Georg Fertig (Turnhout: Brepols, 2015), 281-310.
11. Vanessa van Renterghem, “Structure et fonctionnement du réseau hanbalite bagdadien dans les premiers temps de la domination seldjoukide (milieu du Ve/XIe siècle),” in Espaces et Réseaux en Méditerranée Vie-XVIe siècle 2, eds. Damien Coulon, Christophe Picard, and Dominique Valérian (Saint-Denis: Éditions Bouchène, 2007), 207-232.
12. Michel Balard, “Les actes notariés génois: sources pour une histoire des réseaux marchands (XIIe-XIVe siècle),” in Quel mar che la terra inghirlanda. In ricordo di Marco Tangheroni, 2 vols., eds. Franco Cardini and Maria Luisa Ceccarelli Lemut, Collana Percorsi, 14 (Pisa: Pacini, 2007), 1:103-115.
13. Antonella Rovere, “Cancelleria e documentazione a Genova (secoli XII-XIV),” in Studi in memoria di Giorgio Costamagna (1916-2000), ed. Dino Puncuh, Atti della Società Ligure di Storia Patria, n.s., XLIII/I (Genoa: Società Ligure de Storia Patria, 2003), 909-942.
14. Craig Muldrew, “‘Hard Food for Midas’: Cash and Its Social Value in Early Modern England,” Past and Present 170 (2001): 78-120.
15. Vito Piergiovanni, "I banchieri nel diritto genovese e nella Statutaria Europea tra Medioevo ed Età Moderna," Atti della Società Ligure di Storia Patria, n.s., LII/I-2 (2012), 971-986.
16. Enrico Spagnesi, Aspetti dell’assicurazione medievale (Milan: Giuffrè, 1975).
17. Gino Luzzatto, La commenda nella vita economica dei secoli XIII e XIV con particolare riguardo a Venezia (Padua: Litotipografia editrice universitaria, 1934), and Gino Luzzatto, Storia economica di Venezia dall’XI al XVI secolo (Venice: Centro internazionale delle arti e del costume, 1961).
18. Reinhold C. Mueller, “Bank Loans to the Venetian State,” in The Venetian Money Market: Banks, Panics, and the Public Debt, 1200-1500 (Baltimore: Johns Hopkins University Press, 1997), 541-78.
19. Ellen E. Kittell, “Testaments of Two Cities: A Comparative Analysis of the Wills of Medieval Genoa and Douai,” European Review of History 5, no. 1 (1998): 47-60.