MEDIATE seeks to study the circulation of books and ideas in eighteenth-century Europe by drawing on a unique corpus of 2000 - 3000 eighteenth-century private library catalogues. Developing an interoperative, Open Access database, and in close collaboration with other existing historical bibliometric databases, MEDIATE harvests data from a corpus of catalogues of smaller private libraries sold at auction in the Dutch Republic, France, Italy, and the British Isles between 1665 and 1830. MEDIATE hypothesizes that, to understand the spread of ideas and books associated with the Enlightenment movement, it is crucial to understand how these books were embedded in the cultural field at large, i.e. the literary system as a whole.