When Anton Pannekoek left Dutch astronomy in 1905, he left a stagnating, uninspiring research community. When he returned a decade later, things started to change in the Dutch astronomical community. By the mid-1920s, De Sitter, Hertzsprung, Oort, Minnaert, and Pannekoek had built a flourishing discipline. Through their work and students, they shaped Dutch astronomy for the rest of the twentieth century. This paper focuses on Pannekoek’s return to astronomy and his role in Dutch astronomy in the Interwar period. First, I will provide a detailed reconstruction of his failed appointment at Leiden Observatory in 1918-1919. After that, I will analyse how he could play an influential role, even though he had little staff, students, or facilities at the University of Amsterdam.

In the late 1950's Freudenthal published several articles on the history of geometry around 1900, in particular on Hilbert's innovative approach to the foundations of geometry. Especially his essay-review of the eighth edition of Hilbert's Grundlagen der Geometrie has become a standard reference in historical studies of geometry. In the present article I discuss Freudenthal's contribution to our understanding