Arnold Clapmarius’ ‘Traineeship in politics’. Practical Experience and the Semblance of Practical Experience as a Qualification in the Field of Political Science around the Year 1600. In 1600, Arnold Clapmarius (1574–1604) was appointed the first professor for Public Law and Political Science in the Holy Roman Empire by the University of Altdorf (Nürnberg). He received this professorship though he had not yet published anything because he was a protégé of Landgrave Maurice the Learned of Hesse‐Kassel. Two newly discovered letters which were written by Clapmarius to Maurice show that the young scholar did a traineeship at the Landgrave's court to gather practical experience in politics. This was probably the reason for his appointment in Altdorf. Nevertheless, he hushed up this traineeship because it did not comply to the kind of experience that were expected from a ‘politicus’ at that time, id est military service, educational journeys, foreign languages and regional studies. Thus, this paper fills a gap of Arnold Clapmarius’ biography, and provides a new perspective on the value of practical experience in the field of political science in the Early Modern Period.