Actors in the changes of ICMI: Heinrich Behnke and Hans Freudenthal.

The years after WWII up to the late 1960s were crucial in the evolution of ICMI (International Commission on Mathematical Instruction) for both the settlement of some institutional aspects (mainly concerning the relationship with mathematicians) and the establishment of new trends of the activities. By referring to unpublished documents, this paper focuses on the role of two key figures in those years: Heinrich Behnke and Hans Freudenthal. As ICMI Secretary and later as President, Behnke tried to reshape the newborn ICMI after WWII and clarify the relationship with mathematicians. His action was completed by Freudenthal, who, as ICMI President, broke with the past and promoted initiatives that fostered the development of mathematics education as an academic field and the independence of ICMI from the community of mathematicians .