This copy of 'The Canterbury Tales' was produced in the 1430s. Credit: Brigade Piron / Wikipedia CommonsEvery book was a laborious project during the Middle Ages. And according to a first-of-its-kind quantitative review, more than a few of them were penned by women.Experts estimate medieval scribes produced over 10 million manuscripts between 400-1500 CE, each one painstakingly copied, illustrated, and bound by hand. Only around 750,000 still exist today, but there is still plenty to learn from the surviving artifacts, as well as the artisans who created them. But while most books were written by monks hunched over desks in monastery scriptoriums for hours at a time, that wasnt always the case. The striking historical revisions are detailed by researchers from Norways University of Bergen in a study published last month in Humanities and Social Sciences Communications.The authors noted that while previous studies examined gender roles in monastic scriptoria, none attempted to calculate how many women contributed to these intense undertakings. To begin their study, the team relied on a common section found in most medieval manuscripts called a colophon. Ostensibly a publishers biography, scribes often included colophons at the end of books to record their name, who commissioned the project, date of production, and sometimes even a short reflection statement.The full text of this colophon reads: Ego Birgitta filia sighfusi soror conventualis in monasterio munkalijff prope Bergis scripsi hunc psalterium cum litteris capitalibus licet minus bene quam debui, orate pro peccatrice (I, Birgitta Sigfuss daughter, nun in the monastery Munkeliv at Bergen wrote this psalter with initials, although not as well as I ought. Pray for me, a sinner). The colophon has entry number 2235 in the Benedictine collection. Credit: . Ommundsen et al., Humanities and Social Sciences Communications (2025) First, researchers turned to an existing catalogue of Benedictine colophons, reviewing all 23,774 entries for linguistic confirmations of gender. A total of 254 were linked to female scribes, with 204 featuring the names of the women themselves. This comes out to roughly 1.1 percent of the Benedictine databases books.Using existing estimates for manuscript production and loss we may infer, under the assumption that the estimates are valid, that at least 110,000 manuscripts were copied by female scribes, of which around 8,000 should still exist, the researchers wrote.While a modest number, researchers cautioned their estimate is likely lower than the actual total. Many women may have purposefully omitted their gender or name in their colophons, or simply did not include them at all. Meanwhile, varying manuscript survival rates across geographies could also have skewed the data.One thing is almost certain: the number of known female scriptoria described in existing records likely could not have produced all of the estimated 110,000 women-penned manuscripts. Because of this, the team believes their investigation strongly suggests that there are female book-producing communities not yet identified. Another possibility is that there simply may have been many more female scribes, than we thought.Our study should be seen as a first step, opening new perspectives, wrote the authors.