Yearning princesses locked away in castles, heroic knights, hawkish Vikings — fragments of medieval European stories have permeated nearly every aspect of contemporary culture, from Taylor Swift songs to Shrek. But how many stories haven’t survived to the modern day? A recent study published in Science found that nearly one-third of Medieval tales and over 90% of original manuscripts have been lost forever.

The study, titled “Forgotten books: The application of unseen species models to the survival of culture,” examined medieval European manuscripts written in English, French, Dutch, German, Irish, and Icelandic. Instead of focusing on all medieval manuscripts, many of which are religious texts, the study focused on narrative and chivalric fiction — tales that include sagas of courtly love and stories about King Arthur’s round table. These stories were mainly circulated through manuscripts made from parchment until paper became more common in Europe around 1450.

The study was published by a large team of scholars whose areas of study range from literature to history and biostatistics. The team includes Mike Kestemont, Elisabeth de Bruijn, and Remco Sleiderink of the University of Antwerp in Belgium, Folgert Karsdorp of the KNAW Meertens Institute in Amsterdam in the Netherlands, Matthew Driscoll of the University of Copenhagen in Denmark, and others.

The diverse team took a relatively novel approach to their research: Instead of using methods traditionally used for studying history, the team used a method used in ecology, called the “unseen species model.” This model was developed by biostatistician Anne Chao of the National Tsing Hua University in Hsin-Chu, Taiwan, one of the study’s authors.

The unseen species model is used in ecology to determine how many species go undetected during a survey. This is a pervasive problem in ecology because it is nearly impossible for scientists to observe every single species in a given area. (This problem of “unseen entities” extends to other fields too. For example, astronomers can’t be sure that they accounted for every star, linguists can’t know that they heard every word in a language, and computer scientists can’t know that they found every bug in a program.)

In order to use the model, the researchers had to categorize the Medieval narratives and manuscripts as living things. Each individual story was treated like a species, and each manuscript containing the story was treated like a sighting of that species.

This heatmap shows the locations of libraries and archives where manuscripts are held. The types of manuscripts are categorized by language: Dutch, English, German, and French. (courtesy Science)

Although there is still little quantitative research into the existence of medieval manuscripts, this study did not mark the first time scientific methods have been applied to historical record keeping. A 2007 study examined printed books also using an unseen species model, but two previous studies examining Medieval manuscripts with scientific methods were met with sharp criticism “because the figures obtained did not fit with other historical evidence,” according to the recently published study. The study’s authors went on to explain that conventional approaches rely on mentions of lost works in places like library catalogs, “but many lost works will not have been mentioned.”

There were many ways in which those missing manuscripts were lost: Some were destroyed in events like library fires, but others were lost when the parchment they were written on was repurposed. For example, fragments of manuscripts were used to bind books and wrap meat. Tailors also used them as measuring tapes. They were also used as material for a bishop’s miter.

Some manuscripts were destroyed when they were repurposed. In this example, the parchment from a manuscript was used to reinforce a bishop’s miter.
Fragment of Strengleikar repurposed to stiffen a bishop’s miter, AM 666 b 4to (courtesy Arnamagnæan Manuscript Collection, Copenhagen, Denmark)

Ultimately, the report found that 799 literary tales out of an original 1,170 are still around today. It also found that those stories were written down in a total of 40,614 manuscripts, but only 3,648 of those have survived.

But the study went beyond a general European inquiry, examining which countries’ manuscripts had the highest and lowest survival rates. Germany, Ireland, and Iceland had the highest rates.

In ecology, the species that exist on an island — like Ireland or Iceland — have high species richness and evenness. “A parallel emerges with some of the cultural diversity profiles for island regions reconstructed here: If land-isolated areas preserve biological heritage more effectively, then the same might hold true for cultural heritage,” the study reads.

And the report attributed these results to a previously overlooked factor: the evenness in which manuscripts were distributed. For example, even though France had a vast tradition of medieval literature, since it was not as abundantly produced, a single library fire could render a story extinct.

The country with the lowest manuscript survival rate was England. “French-speaking Normans conquered England in 1066, which may have led to greater neglect and recycling of manuscripts written in English,” reads an article about the study published on Science News.

Kestemont told Hyperallergic that applying the unseen species model is a general method that can be used in other disciplines as well, like social history.

“How much has been lost exactly is a question that has been fascinating me since I was an undergrad,” the researcher said. “Is what we still have nowadays in any way representative of the wealth of books and stories that once existed? I always assumed that we’d never be able to answer this question. Through the unexpected application of a method from ecology, however, we are suddenly able to at least begin to answer this question.”