After a brief account to the task of the Halle herbarium (HAL), its history is described from the foundation in 1819 to 1945. Special attention is given to the most important herbaria of D. F. L. v. Schlechtendal and his father D. F. K. v. Schlechtendal, other holdings are mentioned. New activities in research, started in 1947, stimulated the development and continuous enlargement of the herbarium. The estimated number of specimens in the different plant groups is given. Frequent collectors of flowering plants are named and in addition all bound exsiccata of Cryptogams deposited in HAL. Annotations deal with informations (mainly from unpublished letters) about parts of herb. Lambert in Germany and the collections of Schiede and Deppe, C. A. Ehrenberg, C. Papst, Hohenacker, Drège, Ecklon, and Zeyher.