This proseminar, specially designed for teacher training students, focuses on the discovery and development of mathematics as part of culture and society. From the point of view of "becoming mathematics", the main focus will be on the intra-mathematical development of selected mathematical topics and findings, their historical and cultural contextualisation and the actors involved in this development. In addition, some of these topics and findings will be examined as examples of where and to what extent they have found their way into other areas and contexts, e.g. in art, music, architecture or other scientific disciplines. In the second part of the proseminar, students will prepare small projects independently in group work on a mathematical topic of their choice and present them in the course.