The historical significance of Christian Gottfried Nees von Esenbecks (1776 - 1858) lies in his scientific life's work as a botanist, zoologist and natural philosopher and in his committed socio-political effects. His life and work is in many ways a mirror of the scientific as well as the general history of the first half of the 19th century. Especially in his extensive correspondence lies the key to understanding his work. The corpus of sources with more than 4000 letters provides information on the history of systematic botany, the romantic natural philosophy, the history of the universities of Erlangen, Bonn and Breslau and the science policy of the Prussian Ministry of Culture.
The edition of letters is of fundamental importance for the history of science and culture, which is reflected in national and international activities. The publication of the writings and materials are provided as annotated edition of letters.
In the correspondence between Nees von Esenbeck and the ministers of the teaching and medical matters, these aspects are given a broad scope. The correspondence with the Ministry about the general history of science, universities and academies, including unseen material, could be used for an educational historiography of the natural sciences after 1800.