The collection of the NCB Naturalis comprises more than 11 million objects. It dates back to the 18th century and ranges from specimens collected during the voyages of Captain Cook in the South Pacific and Von Siebold and Bürger in Japan to marine and terrestrial collections from expeditions to South-East Asia as recent as 2005. The Von Siebold collection, the oldest natural history collection from Japan, was collected between 1824-1835 and described by C.J. Temminck & H. Schlegel in the Fauna Japonica.
Coenraad Jacob Temminck (1778-1858), founder, director and ornithologist of the museum, was a true collector. The private collections obtained by his father, his own international reputation, and his drive to exchange specimens with museums in Paris, Vienna, Berlin and London made the Leiden collections of outstanding diversity and beauty. The work of many reknown scientists over a period of nearly 200 years, describing new species from all over the world, explains the large number of type specimens, involving vertebrate, invertebrate, entomological as well as paleontological objects.