5 Mark Robert Koch

Issued to mark the 125th anniversary of Robert Koch's birth, this coin honored the bacteriologist who identified the causative agents of tuberculosis, cholera, and anthrax — work that earned him the 1905 Nobel Prize in Physiology or Medicine. The GDR minted commemoratives like this one with deliberate ideological purpose, claiming scientific luminaries of German history as socialist heritage regardless of their actual politics. Koch himself was a Prussian imperialist who conducted controversial human trials of tuberculin in the 1890s, a chapter his East German commemorators quietly ignored.