The IISH is the most important worldwide repository of anarchist records and papers. Indeed, a vast anarchist collection was among the first acquired when the Institute was founded in 1935, when it received the books and papers of Max Nettlau, the "Herodotus of Anarchy". The latter's extraordinary collection included the personal papers of Michael Bakunin, as well as voluminous documentation on the Russian anarchist and his circle. Nettlau's correspondence with anarchists all over the world is a historic source in its own right, and his library constituted the single largest private collection in the field ever assembled. The presence of Nettlau's collection persuaded others, such as Emma Goldman and Aleksandr Berkman, to deposit theirs at the IISH as well.
The many faces of anarchism are all represented at the IISH: from individual "terrorists" to the founders of peaceful communities; from small groups of intellectuals and artists from Japan and China to the anarchist mass movements that once existed in the Spanish-speaking world, where they played a major role both in the Spanish Civil War and in Latin America. Microfilms of collections held in other archival institutions (e.g., John Mackay, Louise Michel, Kropotkin, and Elisée Reclus in Moscow) complete the IISH collections.
All collections and collection items are retrievable via the IISH catalogue. The Institute is digitizing its leading archives and collections. Documents in the archives of Max Nettlau, Emma Goldman and many others are now fully available to view via the Institute’s catalogue.