Co-Produced Religions: Judaism, Christianity, Islam

Our goal is to provide the foundations of a new history of Judaism, Christianity, and Islam as co-produced communities, a history that makes clear the many different ideas and ideals that each of these communities has formed, and continues to form, by interacting with or imagining the others.

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Source in the Spotlight

On the Destruction of Jerusalem: One Narrative Bedrock of the Historiographical Construction of the Jews

Probably in the early 370s of the Common Era there appeared a Latin text that is often dubbed On the Destruction of Jerusalem (De excidio Hierosolymitano), but which may have simply been called the Historiae initially. Scholarship has long debated whether the Christian bishop Ambrose of Milan wrote the text, but despite recent arguments for Ambrose (Zwierlein 2024; Somenzi 2009), there exists no consensus as to the work’s author, often dubbed “(Pseudo-)Hegesippus” based on a name—(H)egesippus—that begins to appear on manuscripts of the work in the Early Middle Ages (see Figure 2). Where the work was written or where its author was from we do not know. This text is a Latin Christian adaptation of Flavius Josephus’ Greek work, the Jewish War, written around 75 CE (Bay 2023; Bell 1977). Both in conception and in reception, what this text does with Josephus’ narrative lays a bedrock for how Jews came to be understood as a people vis-à-vis their history.

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Latest Case Study

Co-Producing Love and Paradise: The Sicilian School of Poets

The idea of a sensual paradise might seem foreign to medieval Christian devotion. But it was an important motif in the love poetry of the Sicilian School, and likely emerged from interactions between Christian and Muslim poetic traditions in the island’s Norman and Swabian courts. This article explores these hybrid origins – and how nationalist accounts have historically silenced them in favour of exclusively domestic narratives.

Peter of Eboli, Liber ad honorem Augusti (Bern, Burgerbibliothek, Cod. 120.II, lat., f. 101
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Event: International Conference and Workshop

Insular Entanglements: Malta, 300-1700

June 16-19, 2026 Valetta, Malta

International Conference in Valetta, June 16-19th, 2026

Organizers: Mohamad Ballan (Stonybrook University) and Katharina Heyden (University of Bern)

Our upcoming conference "Insular Entanglements: Malta, 300-1700" examines Malta as a case-study of Mediterranean entanglement from Late Antiquity through the Early Modern period. The notion of entanglement that we propose is quite capacious, encompassing not only (nor even primarily) quotidian interreligious interactions but ideas of connections, polemics, memory, histories, and texts more broadly. This will include intellectual networks, economic and political connections, language, cultural encounters, religious thought and polemics, as well as the relationship between the local (Malta) and regional (Mediterranean). The idea of frontiers and borderlands will constitute an important theme of the conference, but we will also explore questions of materiality and material culture in early Christianity, the complex (and ever-changing) relationship between religious and cultural traditions, and the larger political transformations taking place across the medieval and early modern Mediterranean world.

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Latest Publication

Co-produced Religions: Judaism, Christianity, and Islam

Harvard Theological Review 118 (2025), 159-180.

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About

Who we are

The project is coordinated by Katharina Heyden, Professor for Ancient History of Christianity and Interreligious Encounters at the University of Bern (Switzerland), and David Nirenberg, Leon Levy Professor at the Institute for Advanced Study, Princeton (U.S.), and includes a network of collaborators across North America, Europe, and the Middle East.

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