Prior to this, the national library was part of the British Museum, which provided the bulk of the holdings of the new library, alongside smaller organisations which were folded in (such as the National Central Library, the National Lending Library for Science and Technology and the British National Bibliography).
Dessförinnan var nationalbiblioteket en del av British Museum, som gav den största delen av innehavet av det nya biblioteket, tillsammans med olika mindre organisationer som ingick (som till exempel National Central Library, National Lending Library for Science and Technology och British National Bibliography).