Diet and mobility in Late Antique Sicily: Isotopic data from the catacombs of Santa Lucia, Siracusa (Italy)

•The catacombs of Santa Lucia in Siracusa, Italy, constructed during the 3rd century CE, served as a burial ground for the local Christian community until the early 8th century CE.•This archaeological site holds great significance as a burial context from the Late Roman and Byzantine periods, showcasing tombs and artifacts indicating burials of individuals from various social classes.•Historical records confirm the presence of a significant Christian community from Syria and the Levant in Siracusa during this time, adding to the cultural and historical importance of the catacombs.•A research objective was pursued to investigate the life histories of the Late Antique community buried in the catacombs by utilizing stable isotope analysis, specifically targeting stable carbon, nitrogen, and oxygen isotopes.•The stable isotope analysis revealed noteworthy dietary diversity among the individuals interred in the catacombs, showcasing the consumption of both C3 and C4 plants, as well as fish from freshwater and sea sources. Additionally, the oxygen isotopes indicated a wide range, suggesting considerable mobility throughout the lives of most individuals tested and raising intriguing archaeological and historical implications.