From Fragmented Repertoires to a Property Graph. A Queryable Atlas of Byzantine Geometric Mosaic Bands for Architectural Heritage

Research often focuses on architecture as a whole, seeking to explore its various scales as thoroughly as possible. However, some aspects, such as decorative friezes, play a decisive role not only in terms of decoration but also in understanding architecture as a whole. Besides, understanding an entire system of ornamental decorations is linked to resolving specific complexities, which make it difficult to access in its entirety. These include the study of types, their recurrence and comparison, the possibility of inferring connections from common elements, and the accessibility of all these aspects to experts in the field. In fact, comparing historical-artistic ornamental repertoires across sites and periods is often hindered by fragmented documentation and inconsistent terminology, which make systematic verification of recurrences and variants difficult. This paper proposes a methodological framework for constructing an interrogable Atlas of architectural ornament based on a property-graph model, designed to reconnect visual evidence, typological classification, contextual data, and bibliographic sources within a single relational structure. The workflow integrates image-based acquisition and orthometric products, vector reference drawings for typological definition, a controlled thesaurus for terminological normalization, and a repeatable ETL pipeline for data ingestion into a graph database. Within this framework, decorative instances, classes, and morphological families are explicitly linked to architectural context, chronology, images, and sources, enabling evidence-first navigation and controlled comparative analysis. To assess the approach, the method is applied to a case study on geometric mosaic bands, comprising 34 parietal and pavement classes on planar surfaces (5th–12th centuries) in monuments from Ravenna and Rome. The resulting Atlas supports cross-site and cross-period comparison by making typological proximity, variants, and attestations directly inspectable together with their supporting documentation. Rather than a generic digital archive, the contribution defines an operational structure for comparative research on architectural ornament, offering a scalable and verifiable framework for cumulative knowledge building and future extensions.