Tracing lives in isotopes: multi-isotope perspectives on diet and mobility in Fermo (Marche, Italy) during the Iron Age

In recent years, growing interest in dietary habits and mobility in past societies has increasingly drawn the attention of scholars, becoming one of the most discussed topics in archaeological research. This trend has been driven by the development of new and advanced biogeochemical methodologies that have significantly enhanced the study of ancient diet and mobility patterns. In this framework, isotope analysis of archaeological teeth and bones has become a key tool for investigating changes in habitat, animal herding, dietary tendencies and migration patterns in the past. This paper explores the dietary and mobility patterns at the important Early Iron Age site of Fermo (chronology, Marche, central Italy), through a multi-isotopic analysis (δ¹³C, δ¹⁵N, δ¹⁸O, and δ³⁴S) of 30 human tooth samples of inhumed individuals, along with some faunal bone samples for recreating the baseline. Since the first systematic studies, the archaeological site of Fermo – comprising the Misericordia and Mossa necropolises, used from the 9th to the 5th century BCE – has been in a lively scholarly debate. Although situated within the territory traditionally associated with the Picene cultural sphere, both its organizational structure and the burial practices reveal notable affinities with the renowned and intricate Villanovan material culture, along with elements of the Picene tradition itself. The funerary complexity of Fermo has made it one of the most debated Iron Age sites in Italy within the academic community, both in past and recent research. This study is part of a broader research project and aims, first, to demonstrate how a multi-isotope approach can provide a more detailed understanding of dietary and mobility patterns than a single-isotope approach, while integrating with existing isotope data from previous studies at Fermo. Secondly, it seeks to compare these results with data from other contexts across the Italian peninsula to build a comprehensive scenario of the complex social and political dynamics of Iron Age populations.