A unique biography of the Utrecht anchoress Sister Bertken
The Utrecht anchoress Sister Bertken (1426/27-1514) was beloved by the people of the town even in her own time. Utrecht University Library holds a handwritten source that offers unique insight into her life as well as her death. In a printed collection of saints' lives from 1496 (H fol 252 rariora), a biography of Sister Bertken is inscribed by hand (UBU Hs. 1817).
The Utrecht writer Berta Jacobs, also known as Sister Bertken, lived as an anchoress in a small cell against the Buurkerk for no less than 57 years, from 1456 or 1457 until her death in 1514. This rigorous choice for a life completely devoted to Christ was already looked upon with admiration in her own time. A striking text about her life was written down by a contemporary on the title page of an edition of Jacobus de Voragine's Legenda Aurea.
Golden legends
The Legenda aurea or ‘Golden Legends’ was a widespread collection of biographies of the most important saints. The collection was written down in the mid-13th century by the Dominican cleric Jacobus de Voragine (c. 1230-1298) and was subsequently distributed throughout Europe, being constantly expanded and adapted to include the lives of regionally venerated saints. In the incunable period, the earliest years of the printing press (c. 1450-1500), the Legenda aurea was published even more often than the Bible.
An anchoress and writer in Utrecht

Precisely in a copy of that book, someone added a biography of Sister Bertken by hand on the title page, as if she too had the status of a saint. Berta Jacobs was born as the (illegitimate) daughter of the high clergyman Jacob van Lichtenberg, who was also one of Utrecht's most powerful political leaders in the 15th century. When she was 30 years old, she had herself locked up as a recluse in a cell against the Buurkerk. She paid for this herself from the sale of an annuity she may have received from her father. There were more women in the late Middle Ages who chose an existence as an anchoress, in seclusion yet in the middle of the city, often with a window that allowed contact with people on the street. Without being able to leave her cell, the anchoress could thus, for example, give wise counsel or receive food. Whether Berta Jacobs also had such a window to the street, we do not know, but in one of her texts she does say that she promised to pray for the people of the city.

She filled her days with praying, meditating, and writing. We can get to know her inner life well because she recorded her personal devotions in her texts, including a meditation on the Passion of Christ, a number of prayers, a tract on Christmas Eve (in which she vividly imagines how Mary must have experienced the birth of Christ) and a number of songs. After her death, many wanted to pay her last respects: accounts preserved in the Utrecht Archive show that six servants received payment to guard her tomb in the Buurkerk. The bells of the Dom were rung twice, as happened when a high-ranking cleric died. But we only know details of her life from the handwritten biography in the incunable of the Utrecht University Library.
Biography “in a glass”
The text added to the title page of the incunable in the University Library collection is written in Middle Dutch in an early sixteenth-century hand, i.e. relatively shortly after Bertken’s death. Remarkably, it contains a number of important details about Bertken that are not known from any other source: her exact date of death (25 June 1514), her (granted) wish to be buried in her own cell and her strict religious penance. The anonymous copyist mentions that she was dressed all year round in a coarse hairshirt on her bare skin, that she did not eat any meat or dairy products, and that she was always barefooted and never had any heating in her cell.
A caption (written in the same hand) explains the nature of this text: it is a copy of the Latin “letter” that had been placed “in a glass” in her coffin, translated into Middle Dutch. Attached to that document were the seals of three senior clerics, including Dirck van Malsen, the prior of the Utrecht canons regular, who also states that he had custody of the keys to Bertken’s cell. It seems, then, that someone literally gave a place to a description of the holy lifestyle of “the devout virgin Berta Jacobs daughter” in the most important collection of saints’ legends, expressing high esteem for the deceased.

Sister Bertken and the Utrecht canons regular
Studies on Sister Bertken have argued that exactly this copy would have been in possession of the Utrecht regulars’ convent where Dirck van Malsen was prior, and that the person who extended the Golden Legends with her biography would therefore also have been one of the canons regular (Snellen 1924, p. I-IV, Van Aelst 1998, p. 262, Handschriften en oude drukken, p. 75-76).
But unfortunately, closer inspection reveals that there is actually no evidence that the incunable with Bertken’s biography came from this monastery. The confusion arose from the assumption stated in the University Library catalogue of manuscripts (Hulshof 1909) that H fol 252 rariora was the second volume of a two-volume edition of the Legenda aurea, with H fol 251 rariora as the first volume. That copy (unlike H fol 252 rariora) still has the original binding, with stamps proving the book’s origin from the canons regular. Indeed, the blindstamping on the binding contains a motif with a pierced heart, the attribute of the church father Augustine, whose monastic rules the canons regular followed. This same stamp was used on several bindings in their possession. This provenance of H fol 251 rariora then linked the supposed second volume to the same institution and thus also the biography of Berta Jacobs.
When the two incunabula are compared, it soon becomes clear that they are not two volumes of the same book, but two identical copies of the same edition, printed in Strasbourg by Georg Husner (as the 1922 incunabula catalogue by Alblas and Van Someren also correctly states). This removes the only argument on the basis of which the copy with the biography was directly linked to the canons regular, as H fol 252 rariora itself contains no indication of provenance.
Data on how both books came into the University Library collection also provide no clues. The copy H fol 251 rariora already appears in the oldest library catalogue of 1608, but H fol 252 rariora with the Bertken document is only mentioned for the first time in the catalogue of 1718. This indicates that this copy took a different path from the books that had already entered the library collection from the Utrecht monastic libraries around 1600. Moreover, H fol 252 rariora is bound in a different way from H fol 251 rariora and they are also rubricated differently. That in itself does not rule out the possibility that they could still have the same provenance, but all things considered, indications that H fol 252 rariora did not belong to the canons regular outweigh indications that it did.
Admiration for Bertken
Even though the copy H fol 252 rariora probably does not come from the Utrecht convent of the canons regular, it is an important source that teaches us more about Bertken than just the remarkable details of her life. The biography was written shortly after her death (based on the hand) by someone who had access to the Latin biography or an earlier copy of its Middle Dutch translation, and who therefore likely came from Utrecht. The tolling of the bell, the fact that Bertken’s coffin could be visited after her death and that many people did so, and that the text apparently placed in it was translated and began to circulate separately, all point to the unprecedented popularity the Utrecht anchoress had gained and to the admiration the inhabitants of Utrecht (and far beyond?) had for her lifestyle.