What Thormod Torfæus (1636-1719), an Icelander serving as royal antiquarian at the Danish court, owned a collection of Old Norse manuscripts, which after his death ended up in the collection of Árni Magnússon, who divided almost all these manuscripts into smaller units. Because of Magnússon's rearrangement activities and the agreement between Iceland and Denmark about the division of his collection, manuscripts which used to be in a single codex in Torfæus' library, today survive in many parts held in two countries. Therefore, their contents can no longer be seen in their entirety. My project employs the latest tools in digital preservation and cataloging to restore the dispersed manuscripts, and to make accessible, for the first time, the library of this important scholar to wider audiences. Why Torfæus examined the Old Norse sagas as historical sources and commented extensively on various historical and cultural aspects of these texts in the margins of his manuscripts. This project analyses these sagas and the marginal annotations that accompany them in the context of virtually reconstructed manuscripts in order to answer research questions considering Torfæus' working methods as a historian, book collector, and commissioner. Torfæus' marginalia are valuable sources for the history of early modern Danish historiography, but they have hitherto remained unanalyzed, due to the dispersed state of his collection. This project is the first study of the entire corpus of his annotations which will provide insight into the early modern processes of knowledge creation and classification. How This project expands upon traditional philological analysis with codicological examination of physical artefacts and innovative digital tools and methods applied to expand our knowledge and understanding of early modern scholarship. A basis of the project will be an Open Access database of Torfæus' manuscripts, which will include manuscript descriptions and virtual reconstructions of selected manuscripts. The digital encoding of the marginal annotations will enable me to develop analytical framework for the data classification, which will shed new light on the reception of Old Norse literature in early modern Denmark. Collaboration with the specialists from world-leading research institutes in Europe, UK, and the US, will assure necessary support to successfully conduct this project. SSR Torfæus, on request of king Frederik III, was the first to compile the oldest Danish royal genealogy based on Old Norse sources, which contradicted the traditional succession presented by Saxo. By doing that, Torfæus influenced the Danish perception of Old Norse-Icelandic material, which eventually became part of the Danish literary canon, so that even today Danish high school students read works such as the Poetic Edda and Njáls saga, as a part of their education. Considering the long-lasting reception of Old Norse literature in Denmark, it is culturally important to engage critically with the origins of enquiry into Old Norse sagas in Denmark and its important role in conceptualizing Danish national history.