In this article I provide a historical and bibliographical exploration of the handwritten, dictated commentaries (dictata) of Johannes de Raey (1620/1622–1702) on the texts of René Descartes, shedding light on their structure, development, and on their relations with the academic commentaries of Johannes Clauberg. The study of these commentaries, which are extant as class notes, is important because they conveyed one of the first systematic teaching of Descartes’s ideas, and constituted a vehicle of their further dissemination across Northern Europe