Advancing Annotation of Historical Maps: ATRIUM TNA Fellowship at ACDH-CH

Advancing Annotation of Historical Maps: ATRIUM TNA Fellowship at ACDH-CH

By Maria Ilvanidou, Digital Curation Unit, IMSI, Athena RC

From May 25 to June 8, 2025, I had the opportunity and the pleasure to spend two weeks as an ATRIUM TNA Individual Access fellow at the Austrian Centre for Digital Humanities and Cultural Heritage (ACDH-CH) of the Austrian Academy of Sciences. My project focused on exploring the use of controlled vocabularies as a systematic approach for annotating historical maps, bringing consistency and reusability to the process of describing features on late 18th and early 19th century maps of Greece and the Balkans.

Aims and Context

Historical maps are complex artefacts: they combine textual and visual features, they carry geographical and cultural information, they capture changing territories, place names, and even lost landscapes, they embed narratives of power and identity, and they are full of interpretative challenges. To make them more useful for historical and archaeological research, it’s essential to move beyond simple digitization and documentation, and towards structured annotation. This will make images machine readable and searchable, unlocking hidden layers of information, and allowing metadata enrichment and meaningful analysis or visualization. My main aim at ACDH-CH was to create a practical vocabulary framework to support this work, using the Centre’s expertise and existing tools for managing and publishing controlled vocabularies.

Activities and Collaboration

During my stay, I collaborated closely with the ACDH-CH team on several fronts:

• We worked on identifying key categories for annotating map features, from physical and man-made elements to administrative units and historical monuments. This draft draws on earlier work such as Gkadolou’s ontology for historical maps (Gkadolou 2013, Gadolou and Stefanakis 2013, Gkadolou and Prastacos 2021) and the lessons learned from annotating Rigas Velestinlis’ Charta of Greece , a detailed 18th-century map that served as an important test case during our discussions.
• We worked with Vocabs , ACDH-CH’s digital service for collaborative creation, maintenance and publication of vocabularies and taxonomies of any kind, to test how controlled terms can be structured, published, and converted to SKOS for reuse. We also discussed how map annotation vocabularies can be connected with semantic resources and broader standards, such as CIDOC CRM and other frameworks for historical cartography.
• We examined how the design and use of controlled vocabularies could be integrated into map annotation workflows, such as ATRIUM’s, ensuring that the steps (from term definition to publication) are documented and reusable.

We considered practical questions, such as linking new vocabularies with Wikidata and other open resources.
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Outcomes and Next Steps

The outcome of this visit is a draft version of a structured vocabulary for annotating historical maps. It is organized around physical, administrative, and man-made features, making references to existing ontologies. Using the Charta of Greece as an example also highlighted the complexity of interpreting historic cartographic symbols and the value of aligning them with standard terms.

Next, I plan to expand this draft vocabulary with additional terms, elaborate on its structure, deepen its connections to CIDOC CRM and other ontologies, and do further testing on other historical maps. This will make it useful in practice and help address more questions about how we describe historical places and features depicted on maps.

Conclusion and Acknowledgements

The ATRIUM TNA fellowship has enabled and further advanced my work, as it has been an important step in strengthening the methods we use to understand and capture the rich layers of information hidden in historical maps. I am grateful to the ACDH-CH team (Massimiliano, Vera Maria and Matej) for their warm welcome, expert advice, and the many productive discussions that shaped every part of this work. They made my stay in Vienna, and the ACDH-CH headquarters, a very pleasant and fruitful experience. Since Rigas Velestinlis’ Charta of Greece was central to this work, I had hoped to visit his house in Vienna as a small nod to the fact that his work is still making us think hard about places and their stories. Unfortunately, a sudden cold kept me indoors, but my ACDH-CH colleagues kindly made the pilgrimage for me and shared photos. So, in a way, Rigas still made an appearance in this fellowship after all.

References

Gkadolou, E. 2013. “Historical Map Collections on the Web: Development of Tools for the Retrieval and Promotion of Historical Maps.” PhD diss. [in Greek], Harokopio University of Athens. https://www.didaktorika.gr/eadd/handle/10442/37342  

Gkadolou, E., and E. Stefanakis. 2013. “A Formal Ontology for Historical Maps.” In Proceedings of the 26th International Cartographic Conference, 25 August, Dresden, Germany, ed. Manfred F. Buchroithner, 813.

Gadolou, Eleni & Prastacos, Poulicos. (2021). Historical Cartographic Information for Cultural Heritage Applications in a Semantic Framework. Cartographica: The International Journal for Geographic Information and Geovisualization. 56. 255-266. DOI: 10.3138/cart-2021-0002  

Rēgas, 1797. Charta tēs Hellados en hē periechontai hai nēsoi autēs [kai] meros tōn eis tēn Eurōpēn [kai] Mikran Asian polyarithmōn apoikiōn autēs [Map]. Franz Müller. Harvard University, Harvard Map Collection, G6810_1797_R4_stitched https://iiif.lib.harvard.edu/manifests/ids:24146534