Johan Oosterman is professor of early Dutch literature and director of Radboud Heritage. After obtaining his doctorate in Leiden under Frits van Oostrom, he worked as a postdoctoral researcher in Antwerp on the repertoire of Dutch songs up to 1600. In that project, as well as before and after, he worked extensively with primary sources in historical collections. Research into collections also plays a major role in the collaboration with Johns Hopkins University Baltimore. In 2014, he initiated the project on Maria van Gelre and her prayer book. He was guest curator of the exhibition Ik, Maria van Gelre (I, Maria van Gelre), which took place from 13 October 2018 to 6 January 2019 at Museum Het Valkhof in Nijmegen.