Unravelling the link between the simulacra of St Clemente of Palácio Nacional de Queluz and St Fortunato & St Semuc of Santa Casa da Misericórdia de Almada

This work presents a comparative osteological, material, and technical investigation of three 18th-century simulacra preserved in Portugal, aiming to clarify their origin, circulation, assembly, and shared workshop practices. Archival documentation and authentication seals confirmed their Roman origin and circulation during the 1770s. Radiocarbon dating places the skeletal remains between the 3rd and 5th centuries, spanning both periods of Christian persecution and subsequent imperial consolidation. Osteological, radiographic, and endoscopic analyses revealed differing anatomical configurations: St Semuc and St Fortunato incorporate remains from multiple non-adult individuals, assembled through deliberate substitution and consolidation practices, whereas St Clemente preserves a largely complete and anatomically coherent skeleton of a probable young adult male. Nevertheless, a similar assemblage for the body was uncovered for all simulacra . Facial modelling relied on silk gauze tiers, stiffened with various organic materials, alone or mixed, including proteinaceous and resin binders, such as collagen-based glues and conifer colophony-type. Imaging-based morphometric analysis was used to explore the weave type, and similar morphometric parameters were estimated, indicating a deliberate and coherent choice of gauze type. Ultimately, SEM-EDS showed that "false gold" strips (gilt-silvered-copper strips) were used in the simulacra's helmets. Overall, the interdisciplinary approach evidenced that simulacra were assembled as devotional reliquaries likely in Rome, and that they shared the same workshop or similar workshop practices.