Migration and mobility in Roman Beirut: The isotopic evidence

•This paper presents the first study implementing a biomolecular approach, through Sr and O isotope analysis, towards the study of ancient mobility in Roman Beirut.•Local baselines for Beirut are established through the analysis of archaeological faunal samples and the compilation of geological and botanical data.•Migrants and potential incomers from diverse geographic origins are identified. The archaeological evidence, in combination with the isotopic data, aids in distinguishing colonists from non-colonial migrants to the city.•Females moved to Beirut during the Roman period as part of the colonist settlement in the city, as well as non-colonial migration to the region. Rescue excavations in Beirut, Lebanon, have uncovered large burial assemblages dating to the Roman period. As the first Roman colony in the Near East, the human skeletons from Beirut provide a unique opportunity to explore migration to the city using biomolecular analyses. This study applies strontium and oxygen isotope analysis to nineteen human skeletons and establishes primary local reference values through the analysis of human and faunal dentition and the utilisation of already available environmental and botanical data from Lebanon. Two possible incomers and two definite migrants – both male and female – were identified who originated from different parts of the Empire. The comparison of isotopic data with the material culture of the graves illustrates how migrant identity is not always expressed in burial, and also how archaeological data can supplement biomolecular results in identifying the type of migration involved in a colonial setting. The results from this study contribute to our understanding of the Roman colonization of Beirut, highlight female mobility during the Roman period, and establish local human isotope ratios which can be used in future research on migration to the city and in the region.