The edge of the Empire: diet characterization of medieval Rome through stable isotope analysis

This paper aims to define the dietary profile of the population of early medieval Rome (fifth–eleventh centuries CE) by carbon and nitrogen stable isotope analysis. This period was characterized by deep changes in the city’s economic, demographic, and social patterns, probably affecting its inhabitants’ nutritional habits. Carbon and nitrogen stable isotope analysis of bone collagen was used to detect the nutritional profile of 110 humans from six communities inhabiting the city center of Rome and one from the ancient city of Gabii. Thirteen faunal remains were also analyzed to define the ecological baseline of the medieval communities. The isotopic results are consistent with a diet mainly based on the exploitation of C3 plant resources and terrestrial fauna, while the consumption of aquatic resources was detected only among the San Pancrazio population. Animal protein intake proved to be similar both among and within the communities, supporting a qualitatively homogenous dietary landscape in medieval Rome. The comparison with isotopic data from the Imperial Age allowed us to detect a diachronic nutritional transition in ancient Rome, in which the collapse of the Empire, and in particular the crisis of economic power and the trade system, represented a tipping point for its population’s nutritional habits.