More than 90% of medieval literature manuscripts have been lost, researchers suggest

Among the most important artefacts from the medieval past are the manuscripts that contained the stories and tales from the period. However, a new study suggests that more than 90% of these manuscripts created in medieval Europe have not survived to the present day, and with it as much as a third of medieval literature has disappeared too.

The findings are published in the latest issue of the research journal, Science. A team of manuscript scholars from Belgium, Denmark, England, Ireland, the Netherlands and Taiwan carried out an examination of survival rates of medieval texts and manuscripts using models developed in ecology studies. In that field researchers estimate how many rare species are missing based on the surviving numbers.


The team also calculated the survival rates for six medieval language areas separately and observed that there are huge differences in these survival rates within Europe. Mike Kestemont, professor of computational humanities at the University of Antwerp and one of the lead authors of the study, says, “We suspected ecologists’ statistical methods to predict numbers of rare species could also be used to estimate numbers of lost literary works and we were right.”

Heatmap of the geolocations of the libraries and archives where documents are kept for four vernaculars

This approach enabled them to estimate the size of the original population of works and of documents, respectively, as well as the losses that these cultural domains sustained, across six vernaculars (Dutch, French, Icelandic, Irish, English, and German). The authors note some of their observations have not been noticed before and challenge existing assumptions. The 3,648 medieval documents in the six vernaculars that are still observable today constitute a sample from a population that originally would have counted 40,614 specimens, they say. This translates to 9% survival rate.


With respect to works, they estimate that about 68% survived, though they did observe considerable inter-vernacular variation, such as the relatively poorly surviving English works (38.6%). Further to the authors’ surprise, works for two of the more insular island cultures, Icelandic and Irish, were relatively intact, with survival rates of 77.3% and 81.0%, respectively. Additional analyses revealed something about these island literatures that has been overlooked in historical discussions of the survival of historic literature; namely, that they had a higher “evenness” – or more even distribution of copies for a given work – which helps create stability in the face of disasters like library fires. Evenness, say the authors, mirrors a special feature of islands as studied by ecologists: the endemic species richness is higher on islands than on the mainland. By contrast to what the authors saw for Icelandic and Irish works, the vaster medieval French literature had a low survival rate for works, which the authors attribute to many of its works being low in abundance (lacking evenness), rendering them more susceptible to immaterial loss.

Forgotten Books — Science (2022) from Forgotten Books on Vimeo.

Daniel Sawyer, the Fitzjames Research Fellow in Medieval English Literature at Merton College, Oxford, and another member of the research team, notes, “We found notably low estimated survival rates for medieval fiction in English. We might blame the dissolution of the monasteries under Henry VIII, which did scatter many libraries. But heroic stories in English rarely appear in the library catalogues of monasteries and friaries in the first place.

“Another possible explanation might be found in the limited prestige of the English language during this period. Today, English is learned as a second language all over the world but, during the Middle Ages, it had little international significance. After the Norman Conquest, in particular, French was important in England as an international language of power and culture, and the English crown owned parts of what is now France. In fact, if we add fiction written in Norman French in England to the evidence in English, the survival rate for English evidence looks more like the rates for other languages. This shows the importance of Norman French to English culture, and suggests heroic stories in Norman French and in English formed a connected tradition.”

Recently discovered fragment of a French manuscript containing the epic story of Anseÿs de Gascogne. Antwerp, University Library, MAG-P 64.21

“This is an exciting collaboration between science and the humanities, between ecologists, statisticians and manuscript scholars,” says Pádraig Ó Macháin, Professor of Modern Irish at University College Cork. “Ireland endured huge losses of its medieval manuscripts over the centuries, but this is the first attempt at quantifying those losses, at comparing them to trends in other countries, and at estimating how those losses affected the loss of individual texts – prose tales in this instance. Such was the distribution of these tales across many manuscripts that stories could still survive in single copies despite the loss of multiple other copies. In this regard, the affinity between the island cultures of Ireland and Iceland is particularly remarkable.”


The team believes its work opens up a new line of research in the study of human cultures of the past. There is nothing specific to ecology or medieval literature about the method used. Its applicability is far wider, and it could be used across the heritage sciences. For the present it is hoped to continue the research in order to learn more about lost books and writings.

The article, “Forgotten books: The application of unseen species models to the survival of culture,” by Mike Kestemont, Folgert Karsdorp, Elisabeth de Bruijn, Matthew Driscoll, Katarzyna A. Kapitan, Pádraig Ó Macháin, Daniel Sawyer, Remco Sleiderink and Anne Chao. appears in Science. Click here to access it.

See also the project website – Forgotten Books: The Application of Unseen Species Models to the Survival of Culture


Top Image: Lavishly illustrated German manuscript containing the Arthurian romance of Wigalois. Leiden, University Library, Ltk 537, f. 71v-72