The Decem libri historiarum of the Bishop of Tours, Gregory (d. 594), are considered to be among the most significant sources on the fundamental changes from the ancient to the medieval world in the Latin West. The artful interweaving of history, pastoral power, and politics, which provided readers with a new history of Christianity and the Christian Church in a post-Roman kingdom, was extremely successful. Almost every historian in the early medieval Frankish kingdoms used Gregory’s historia, reworked it, and continued the history into their own times. However, as many extant manuscripts of Gregory's Histories impressively demonstrate, later historians were still interested in what the original narrative of Gregory had to offer. Here too, Gregory’s text did not remain unchanged and intact just as he had left it (as he explicitly hoped at the end of the Histories), but circulated soon in various versions. Already in the century after his death, a version of the History became particularly popular which presented only the first six of Gregory's ten books. Despite this reduced form, numerous chapters were still omitted from these six books. As popular as this version was, it did not replace the complete version. Gregory's ten-book version continued to be read and further copied. After the end of the Merovingian period, yet another version was created in the historiographical workshops of the Carolingian kingdom and empire. The compilers used all ten books to produce their selection, and distributed them among nine books in order to add as Gregory’s tenth book the narrative of the Merovingian Fredegar-Chronicle and its Carolingian continuation up to the year 741, the year in which the first Carolingian king, Pippin, came to power.

These Carolingian versions provide a particularly interesting insight into how later generations worked with Gregory's foundations and developed his vision further. A meticulous examination of the extant manuscripts reveals numerous traces that the Carolingian historians compiled their new history from several circulating versions of Gregory’s text. Furthermore, changes to the text and marginalia show that the texts were also further worked on, sometimes modified, or compared with other, possibly novel, sources. Each of these manuscripts was produced and treated as a new original. In their production, the template of the selection of nine books and the integration of the Fredegar-Chronicle and its sequels as a tenth book was followed. However, in hardly any of the surviving manuscripts do we find the same selection of chapters.

A particularly striking example of the Carolingian versions is a former compendium from the Abbey of Saint-Bertin, now divided into three manuscripts (Saint-Omer ms 697 + 706 and Bruxelles, KBR, ms. 15835). Although the extant history book was copied in post-Carolingian times, its multifaceted traces lead us back to the original compilation in late Carolingian Reims. It was a comprehensive historiographical compendium whose narrative reached from the foundation of Rome to the Carolingian regnum Francorum around 900. The compilers of the history book not only integrated the circulating Carolingian template into the overarching narrative, but also significantly rearranged it. In addition to numerous subtle textual modifications, passages from another Frankish chronicle, the Liber historiae Francorum, were woven into Gregory's text. This prompted scholars to classify the version in question as inadequate and contaminated. However, in this project, we demonstrate that the innovative and complex adaptations were deliberate attempts to portray a specific alternative of the Frankish past. We raise questions about the employed historiographical practices, the role of gender in the reworking process and the function of this history book in the political context of the late 9th century. The compendium is being analysed by Leon Pürstinger  (Vienna) as part of a book project within this framework (for now, see Pürstinger, Die Geschichte einer fränkischen Weltgeschichte, 2024).

In the project, we also develop and experiment with new digital and computational tools to compare how the potential of Gregory's stories was adopted and adapted in different contexts of the Carolingian and post-Carolingian world. These new approaches allow us to evaluate the degrees of difference and similarity in the various manuscripts beyond their presentation in printed editions, and therefore help to establish new and more differentiated ways of studying the shifting balance of continuities and discontinuities in the processes of writing and rewriting the history of the Christian West from the early to the high Middle Ages.