Migration and mobility in imperial Rome

Migration to Rome in the Imperial period has been under-researched owing to a dearth of epigraphical and historical evidence, particularly regarding the lower classes. A new set of data has come to light in the form of thousands of skeletons from lower-class cemeteries in Rome's suburbium. Two of these cemeteries, Casal Bertone near the city walls and Castellaccio Europarco in an agricultural area of the Roman suburbs, yielded 183 skeletons for osteological analysis. Combined strontium and oxygen isotope analyses of a subsample of 55 individuals isolated 20 people who came to Rome following a birth elsewhere. Carbon and nitrogen isotope analysis of the same sample population demonstrated that there were significant differences between the childhood diet of immigrants to Rome and that of the locals. Immigrants were more likely to have consumed diets with significant amounts of the C4 plant millet. Prevalence of skeletal and dental diseases, however, were not significantly different between the immigrant and local populations. Mobility in Imperial Rome can thus be characterized from isotope analyses as long-distance migration from the provinces as well as movement of individuals within the Italian peninsula. The biological identification of immigrants to Rome in the absence of historical and epigraphical data is a significant first step towards a new understanding of who migrants were, where they came from, and what experiences they had upon arrival in the Imperial capital