The International Institute of Social History (IISH) is the world's largest documentation and research centre in the field of social history. Since its foundation in 1935, the institute has dedicated itself to the collection, preservation and availability of the heritage of social movements worldwide. The institute is independent and reliable, which makes it a natural depository of the frequently threatened cultural heritage of the labour movement and other emancipatory groups and currents. The research department of the institute focuses on the history of labour relations and organizes international projects in this field. The collection (archives, library and audio-visual materials) takes up well over 30 miles of shelf room. The IISH is an institute that comes under the Royal Netherlands Academy of Arts and Sciences (KNAW).