The museum is home to life and earth science specimens comprising some 80 million items within five main collections: botany, entomology, mineralogy, paleontology and zoology. The museum is a centre of research specialising in taxonomy, identification and conservation. Given the age of the institution, many of the collections have great historical as well as scientific value, such as specimens collected by Charles Darwin. The museum is particularly famous for its exhibition of dinosaur skeletons and ornate architecture—sometimes dubbed a cathedral of nature—both exemplified by the large Diplodocus cast that dominated the vaulted central hall before it was replaced in 2017 with the skeleton of a blue whale hanging from the ceiling. The Natural History Museum Library contains extensive books, journals, manuscripts, and artwork collections linked to the work and research of the scientific departments; access to the library is by appointment only. The museum is recognised as the pre-eminent centre of natural history and research of related fields in the world.
Although commonly referred to as the Natural History Museum, it was officially known as British Museum (Natural History) until 1992, despite legal separation from the British Museum itself in 1963. Originating from collections within the British Museum, the landmark Alfred Waterhouse building was built and opened by 1881 and later incorporated the Geological Museum. The Darwin Centre is a more recent addition, partly designed as a modern facility for storing the valuable collections.
Like other publicly funded national museums in the United Kingdom, the Natural History Museum does not charge an admission fee. The museum is an exempt charity and a non-departmental public body sponsored by the Department for Culture, Media and Sport. Catherine, Duchess of Cambridge is a patron of the museum. There are approximately 850 staff at the Museum. The two largest strategic groups are the Public Engagement Group and Science Group.
The foundation of the collection was that of the Ulster doctor Sir Hans Sloane (1660–1753), who allowed his significant collections to be purchased by the British Government at a price well below their market value at the time. This purchase was funded by a lottery. Sloane's collection, which included dried plants, and animal and human skeletons, was initially housed in Montagu House, Bloomsbury, in 1756, which was the home of the British Museum.
Most of the Sloane collection had disappeared by the early decades of the nineteenth century. Dr George Shaw (Keeper of Natural History 1806–13) sold many specimens to the Royal College of Surgeons and had periodic cremations of material in the grounds of the museum. His successors also applied to the trustees for permission to destroy decayed specimens. In 1833 the Annual Report states that, of the 5,500 insects listed in the Sloane catalogue, none remained. The inability of the natural history departments to conserve its specimens became notorious: the Treasury refused to entrust it with specimens collected at the government's expense. Appointments of staff were bedevilled by gentlemanly favoritism; in 1862 a nephew of the mistress of a Trustee was appointed Entomological Assistant despite not knowing the difference between a butterfly and a moth.