I am a social historian of the medieval Middle East, and I work with a relatively neglected type of source: documents, especially sources from the Cairo Geniza, a cache of roughly 400,000 folio pages and fragments preserved in an Egyptian synagogue. I also work with Arabic papyri and paper documents from other sources. Most of my research has centered on Egypt and Syria from the tenth century to the fifteenth, with occasional forays into Europe and modernity, both strange preserves into which I rarely venture unchaperoned.

My work centers around a set of related questions: what makes social and religious groups cohere and fragment; how people demanded justice of the state and facilitated or resisted its extraction of resources; how written documents structured the exercise of power and the creation and maintenance of social bonds; and how reconstructing the concrete details of medieval life demand of the historian a use of the imagination that is rigorous rather than fanciful. I have also developed a fascination with decoding the graphic and semiotic features of documents, and with how medieval people did so.

My first book, Heresy and the Politics of Community: The Jews of the Fatimid Caliphate (2008), asked what made Jews accuse Jews of heresy in some circumstances but not in others. The sources I studied persuaded me that rabbinic authority—which historians have considered the great shaper of medieval Jewish communal life—by itself does not adequately explain the coherence of medieval Jewish communities. Bringing non-rabbinic Jews, long-distance traders and the state into the equation better explains how rabbinic leaders depended on others for their legitimacy and authority. In a series of articles on patronage and social reciprocity, I have taken a stab at explaining social glue in general, both binding forms of individual reciprocity (these are pervasive in medieval Arabic sources and Geniza documents alike) and the kind of group solidarity that emerges during religious and political revolutions, and often holds what came before to be corrupt, ignorant, or unjust.

For more than a decade, I have been studying Fatimid documents of state preserved in the Geniza. These are some of our best sources for understanding how medieval Islamic states governed their subjects, and how states balanced two essential requirements that were often in tension with one another: the extraction of resources and the provision of justice. The physical features of state documents—many of which survived recycled as scrap paper—also have the potential to solve a longstanding problem, the dearth of continuously surviving archives from the pre-Ottoman Middle East. The Umayyads, Abbasids, Fatimids and Ayyubids developed complex systems of document production and preservation; given this, I also argue that historians of the medieval Middle East should pay more attention to documentary sources, which tend to get short shrift compared to texts from the Islamic scholarly tradition. I published a pilot article on a Fatimid petition in BSOAS in 2010(link is external), and a pilot collaborative study (link is external)in 2011. Youll find the results of this research in my book The Lost Archive: Traces of a Caliphate in a Medieval Synagogue(link is external) (2020), and in a pair of articles published in late 2019, one on Fatimid state documents(link is external) and the other on the Fatimid petition(link is external).

Together with Sacha Stern(link is external), I spent a few years studying the manuscript sources about the controversy over the calendar between Iraqi and Syrian Jews in 921–22. This is a major event in Jewish history, but it was poorly understood because for more than a century, no one had examined the original sources for it. The standard narrative holds that Saʿadya b. Yosef al-Fayyūmī (882–942), one of the great cosmopolitan rabbinic leaders of the medieval period, won” the dispute by imposing the standard, uniform calendar of Iraqi Jews on the entire Jewish world. The Geniza evidence tells us otherwise. With a better understanding of codicology and easy access to digital images, Stern and I were better equipped to understand how the various parts of the puzzle fit together. The project brought me to one of my favorite places: the elusive but scenic crossroads of the material text, digital imaging and good old-fashioned Wissenschaft. Here(link is external) is a pilot article on the subject; Sachas book appeared in 2019 as The Jewish Calendar Controversy of 921/2 CE(link is external).

Apart from medieval manuscript fragments, I also have an abiding interest in the classical musical traditions of the Middle East, especially theory and performance practice in the Arab, Ottoman, Persian, Andalusi and Iraqi traditions. I play oud, buzuq and classical piano.

I hold a BA in Literature from Yale College, where I wore black, smoked cigarettes and read literary theory; this means that while I welcome a good methodological discussion, I can sniff gratuitous or decorative uses of theory a mile off. After my undergraduate education, I spent two years as an editor of long-form print journalism and four studying the textual history of the Babylonian Talmud. I did my doctorate in history at Columbia with Yosef Hayim Yerushalmi, but most of my Geniza-related training extra muros here at Princeton.

I am passionate about both teaching and collaborative learning, and I encourage a laboratory-like atmosphere among students. I run Princetons Geniza Lab, where undergraduates, graduate students and postdocs can conduct original research as far as their Sitzfleisch and historical curiosity can take them. I advise or co-advise projects on medieval Middle Eastern or Jewish history, and Im especially interested in social and economic history before the Ottomans.