This paper presents a new Linked Open Data (LOD) service and a semantic portal on top of it available on the Semantic Web: League of Nations Sampo. This paper shows, how this system can be used for Digital Humanities (DH) research, application development, and can form a basis for a larger LOD intrastructure. In our case, the system is targeted on studying the prosopography and activities of the League of Nations (LoN) (1920–1946), the fore-runner of the United Nations, and is the first concrete step of a larger initiative “Minutes of Multilateralism” for publishing and using a cloud of Knowledge Graphs (KG) about mutually interlinked international organizations in Geneva and beyond. League of Nations Sampo is based on 27 000 pages of minutes of LoN assembly meetings, a prosopographical knowledge graph about some 3100 people mentioned in the minutes, and contextualizing data about the real world. For the first time, this wealth of historical documentation is now openly available as FAIR LOD for DH research and practical application development, as demonstrated by the new League of Nations Sampo portal.
