This dataset contains a central ontology used for the linking and integration of digital cultural data as used in research projects in Saxony, Germany. It is applied by six Saxon non-university Digital Humanities research institutions within the DIKUSA-project (Vernetzung digitaler Kulturdaten in Sachsen). It is used as a common core ontology to harmonize the data of the partners which internally use their own specialized ontology for creating research-related knowledge bases. Central categories of the ontology are person, place, group, object, bibliographic item and event. The ontology is provided as an RDF(star)-file in turtle-format. SHACL-constraints for validation of knowledge bases against the schema are included.