Dr. Gion Wallmeyer

Publications

Books

• Wissen über Ungewisses. Politische Berater und die spätmittelalterlichen Kreuzzugspläne (1274–1336) [engl. Knowledge about the Uncertain. Political Advisors and the Plans for a Crusade in the Later Middle Ages (1274–1336)], (Europa im Mittelalter 43), De Gruyter: Berlin / Boston 2023.

Articles (peer-reviewed)

• Les conseillers politiques et la croisade. Les projets des Hospitaliers pour conquérir Rhodes (1306–1310), in: Francia 52 (2025) (accepted).
• (with Jan-Hendryk de Boer, Marcel Bubert, Michele Campopiano, Vanina Kopp, Silvia Negri, Christian Neumann, Daniel Pachurka and Maximilian Schuh) Epistemische Rivalitäten. Zum Umgang mit Sonderwissen an den Höfen des 14. Jahrhunderts [engl. Epistemic Rivalries. Dealing with Specialist Knowledge at 14th-Century Courts], In: Historische Zeitschrift 317/3 (2023), pp. 572–611.
• Zur falschen Zeit am rechten Ort. Der Kreuzzugsplan des Bischofs von León neu datiert [engl. In the Right Place at the Wrong Time. The Bishop of León’s Plan for a Crusade Redated], in: Historisches Jahrbuch 142 (2022), pp. 447–462.
• With Pen and Sword. Knights as Crusade Advisors between the 12th and 14th Century, in: Francia 46 (2019), pp. 453–468.

Book chapters

• Die Absichten der Toten. Ein okzitanisches Medium strukturiert die soziale Welt [engl. The Intentions of the Dead. How an Occitan Medium structured the Social World], in: Bubert, Marcel / de Boer, Jan-Hendryk (Ed.): Die Absicht der Anderen. Zur sozialen Wirksamkeit von Intentionszuschreibungen im europäischen Mittelalter, De Gruyter: Berlin / Boston 2026 (accepted).
• The Knowledge Network of Marino Sanudo Torsello (*c. 1270 †1343), in: Scheller, Benjamin / Villanti, Nicolò (Ed.): People of the Adriatic. Mobility and Exchange in a Venetian Space (XIV–XVI Century) (Venetiana 27), Viella: Rome 2025 (accepted).
• Zwischen Verzicht und Verlust. Visionäres Charisma an der Wende zum 13. Jahrhundert [engl. Between Renunciation and Loss. The Charisma of Visionaries at the Turn of the 13th Century], in: Winterhager, Philipp (Ed.): Verzicht. Mediävistische Perspektiven, Herder: Freiburg i. Breisgau 2025, pp. 33–65.
• Wie der Kreuzzug marktfähig wurde Überlegungen zur Anwendung des Marktbegriffs auf das höfische Ratgeberwesen des 13. und 14. Jahrhunderts [engl. How the Crusade got marketable. Reflections on the Application of the Concept of Markets to Courtly Counselling in the 13th and 14th Centuries], in: Füssel, Marian; Knäble, Philip; Elsemann, Nina (Eds.): Wissen und Wirtschaft. Expertenkulturen und Märkte vom 13. bis 18. Jahrhundert, Vandenhoeck & Ruprecht: Göttingen 2017, pp. 279–312.

Review articles in „Deutsches Archiv für Erforschung des Mittelalters“, „H-Soz-Kult“, „Médiévales“ and „Quellen und Forschungen aus italienischen Archiven und Bibliotheken“.

Research Projects

Religious Charismatics and Social Change (c. 800-1130)
The research project examines the relationship between stability and social change in the core areas of the former Carolingian Empire from the 9th to the early 12th century, by focusing on religious charismatics. It addresses the issue that, since the cultural turn, historical research has tended to view social change predominantly through the lens of conflict and crisis, overlooking the possibility of change occurring without conflict. The study aims to merge and reconceptualise two international debates on social change in the years 1000 and 1100, referred to as 'feudal transformation' and 'church reform' in the field of medieval studies. To achieve these goals, the project adopts concepts from the sociology of religion and differentiation theory, shifts its focus to new historical sources, and applies quantitative methods from the digital humanities. Central to this endeavour is the depiction of religious charismatics, such as saints, visionaries, and hermits, in hagiographical texts, including miracle collections and visions, which have largely been neglected in discussions about feudal transformation.

Assuming that charismatic figures served as a medium for societal self-observation and provided a coping mechanism during times of change, the project aims to understand how these individuals observed society and its changes. Drawing on differentiation theory, 'social change' is understood as a transformation in the distinctions that govern communication, which does not necessarily involve conflict. The project identifies the increasing formalisation and clarification of social distinctions - such as those between clergy and laity or loyal and disloyal - as a common feature linking the developments known as 'church reform' and 'feudal transformation'. To assess the potential long-term alteration of social distinctions without emphasising conflicts or crises, the project employs quantitative content analysis, a method derived from the field of digital humanities. This quantitative study will be combined with two qualitative case studies: one focusing on individual charismatics and the other examining the shifting distinctions within a medieval miracle collection that has been revised and supplemented over several centuries. Overall, the project aims to explain social change around the years 1000 and 1100 from a cultural-historical perspective. In doing so, it wants to open up new avenues for historical research beyond medieval studies by conceptualising change and combining qualitative approaches with quantitative methods from the digital humanities.

The Production of Crusade Experts at the Royal Courts of the Late 13th and Early 14th Centuries (completed)
In 1291, the Egyptian Sultan conquered the last crusader strongpoints left in the Levant. Western rulers, however, refused to accept the loss of their Holy Land and immediately began planning a new crusade. In the wake of utter defeat, they started to question existing knowledge and tried to find new ways and means to conduct a crusade. This epistemic crisis of crusading knowledge became the focus of numerous expert advisors who tried to use their expertise to devise sometimes risky, sometimes conservative recovery projects. The project aims to examine the activities of these advisors from the perspective of the history of knowledge by analysing how crusading knowledge was generated, translated and evaluated at Western courts. It combines hermeneutic approaches with quantitative methods from the fields of content analysis and social network analysis.

• Brackweder Arbeitskreis für Mittelalterforschung
• DFG-Network „Die Absicht der Anderen. Zur sozialen Wirksamkeit von Intentionszuschreibungen im europäischen Mittelalter“
• Center for Uncertainty Studies (CeUS)
• Society for the Study of the Crusades and the Latin East
• Mediävistenverband e.V.
• Verband der Historiker und Historikerinnen Deutschlands