Opicinus de Canistris and the Liber de preeminentia spiritualis imperii (1329). Political thought, manuscript tradition and cultural legacy

This thesis focuses on the political and ecclesiological treatise De preeminentia spiritualis imperii by Opicinus de Canistris (1329). This text was composed in a period of intense fights and debates between lay and religious powers: with it, Opicinus attempted to contribute to the papal cause and to gain the favour of Pope John XXII by arguing in support of theses of papal primacy.

The De preeminentia has, thus far, gone substantially unnoticed by scholarship, despite the wide renown of its author, a figure much studied for his production of texts, drawings, maps, and diagrams shrouded by layers of often obscure symbolism. While this treatise has never been thoroughly examined, it has generally been deemed uninteresting and unoriginal. My research, on the contrary, ventures beyond these established scholarly interpretations: it examines all of the manuscript of the De preeminentia in order to evaluate, for the first time, this work in its entirety. In doing so, it adopts a substantial a shift in approach. The matter of the originality of this treatise is, at least partially, set aside, to inquire, instead, into the language and arguments of the text, and what elements it has in common with, or set it apart from, the rest of Opicinus’ works. On the one hand, this thesis highlights the connections of the De preeminentia with the contemporary milieu of the Avignonese curia and with traditional trends of medieval political thought, and, on the other, it contributes to a better understanding of its author.

A detailed study of the manuscript codices also brings forward elements which allow us to evaluate the dissemination and readership of the De preeminentia in the decades and centuries following its composition. Even though most of these sources are already known to scholarship, here they are treated, often for the first time, as historical sources worthy of being studied in and of themselves. My research reconstructs their histories and closely examines their codicological features, in order to gain insights into their contexts of production and circulation, and their roles as historical artefacts. In particular, this thesis concentrates on signs of readership, such as marginal comments or maniculae, for the purpose of outlining the profiles of the readers of the manuscripts and the De preeminentia, and gauging why they were interested in this treatise, and how they received it. Thus, it paints the trajectory of the dissemination of this treatise, and the circulation of its manuscript codices, in the context of political and ecclesiological debates through the decades of the Great Western Schism and of fifteenth-century Conciliarism.

Not only does this study cast a new light onto the De preeeminentia in its original context, and onto the arch of its cultural legacy in the late medieval period, but it also considers all these elements against the background, and as agents of, wider cultural and intellectual trends characterising the late Middle Ages.