Invited Talk: How to use a cloud of Cultural Heritage knowledge graphs

Linked Open Data (LOD) can be published on the Semantic Web as semantic mark-up embedded in HTML documents or as Knowledge Graphs (KG) in SPARQL endpoints, on top of which applications are developed. KGs typically share the same entities, such as persons, organizations, and places, which means that the data in different KGs about the entities can complement (enrich) or contradict each other, if only we knew what entities are the same in different KGs. For this purpose, entity alignment systems are needed. Examples of such systems include, e.g., the Virtual Authority File VIAF.org of national libraries around the world, the international Linked Open Data Cloud, Linked Open Vocabularies (LOV), and Europeana. This talk presents a new data alignment service and semantic portal "SampoSampo - Connecting Everything to Everything Else" implemented on top of a cloud of 26 related Cultural Heritage (CH) KGs and systems in different CH domains, including biographies, genealogy, fiction literature, historical letters, art, military history, parliamentary discussions, and historical opera performances. The novelty of SampoSampo is to show in practise how a data alignment system can be used for five practical use-cases in Digital Humanities research (DH): 1) Using a LOD alignment service to enrich data in other Cultural Heritage LOD services and applications. 2) Providing global search, browsing, and data-analytic tools over a cloud of KGs. 3) Searching and checking data quality issues based on a cloud of KGs. 4) AI-based knowledge discovery in a LOD cloud based on relational search and Large Language Models. 5) Enhancing data literacy by data-analyses over a KG cloud. SampoSampo was published openly on the Semantic Web in January 2026.