Mary of Guelders

The prayer book of Maria van Gelre is a key work in Dutch art history from around 1400. Due to the fragile condition in which it was found, it could not be studied and exhibited. After successful crowdfunding, the Maria van Gelre Prayer Book project was officially launched in 2015. Radboud University, Staatsbibliothek zu Berlin and Museum het Valkhof worked in close collaboration for four years on the restoration of the book, the research and the development of an exhibition. The research has yielded many new insights: it is now clear how the miniaturists worked, which pigments they used, how the book was composed and that Maria played an important role in this. The prayer book has also become available online. This project was completed in early 2019.

Partners & Sponsors

  • Radboud University
  • Staatsbibliothek zu Berlin
  • Museum het Valkhof
  • NWO, the Dutch Research Council (Alfa Meerwaarde)
  • De Ernst von Siemensstiftung
  • Stichting Art, Books and Collections
  • Stichting SSN Nijmegen

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Who was Mary of Guelders?

Mary d’Harcourt, the woman who would later become known under her married name Mary of Guelders, led a tumultuous life. Born in 1378 and raised among the nobility of the French court, she eventually married a duke of high standing and commissioned an extraordinary prayer book of outstanding quality. Read more about her life and prayer book here.


The exhibition I, Maria van Gelre. The duchess and her exceptional prayer book was on display from 13 October 2018 to 6 January 2019 in Museum Het Valkhof in Nijmegen.


Prayer book online

Making a hidden gem accessible to the public was one of the main goals of the crowdfunding campaign for Mary of Guelders' prayer book. This came true in 2017.


For more information, questions or comments, please send an e-mail to