Integrating ontologies, which structure knowledge for the Semantic Web, Enterprise Architecture Management (EAM) standards such as TOGAF® provide a robust foundation for guiding digital transformation in complex ecosystems. The Higher Education Reference Models (HERM), a widely adopted Enterprise Reference Architecture in higher education institutions, serve as a structured framework worldwide. This paper presents the development of a comprehensive RDF-based ontology for HERM, firmly aligned with TOGAF's Metamodel. It details the ontology's class hierarchies, the challenges of semantic mapping to TOGAF, and the automated transformation process from HERM spreadsheets into RDF representations. The ontology captures English and German terminology, with built-in support for additional languages. All results, including tools and ontology files, are made available via Zenodo, ensuring accessibility and further development within the HERM community.