State secrets and a handwritten page by Marx: a look inside the IISG treasury

For ninety years, the International Institute of Social History (IISG) in Amsterdam has curated an extensive collection documenting global labor and social movements. Housed within its secure archives are approximately 6,000 collections, including the only surviving handwritten page of Karl Marx’s Communist Manifesto, which is recognized as UNESCO heritage. Established in 1935, the institute faced significant peril during World War II when Nazi forces sought to seize its vast repository of socialist documentation for use as study material. While many items were dispersed across Europe or hidden, most were recovered after the war.

Today, the institute prioritizes both physical and digital security to protect sensitive information regarding contemporary activists, such as those involved in the Hong Kong umbrella movement. Outgoing director Leo Lucassen and his successor, Lily Knibbeler, emphasize the importance of preserving voices from marginal groups and counter-movements. Amidst modern global anxieties regarding the fragility of democracy and environmental changes, the leadership maintains that the archive serves as a vital resource for understanding the foundations of democratic institutions and ensuring diverse historical perspectives are documented.