Stable carbon and nitrogen isotope dataset from Roman sites in Germania Inferior (Xanten, Tongeren, and Valkenburg)

Stable isotope collagen data (δ¹³C, δ¹⁵N) are presented for human and faunal samples from three major Roman sites in Germania Inferior: Xanten (Colonia Ulpia Traiana, Germany), Tongeren (Atuatuca Tungrorum, Belgium), and Valkenburg-Marktveld (Praetorium Agrippinae, the Netherlands). Isotopic results are reported for 48 samples (representing 32 human individuals and 10 faunal specimens) that met standard collagen quality criteria (yield, C%, N%, C:N ratios). For the Xanten site, 14 individuals were analysed, including 5 individuals for whom both bone and dentine collagen were measured. All faunal remains originate from Xanten. Furthermore, 17 individuals are included from Tongeren (representing three locations: Beukenbergweg, Kielestraat, and ZW Grafveld), and one individual from the Valkenburg site. This dataset expands the isotopic records for the North-Western Roman Frontier, supporting research on Roman dietary practices and human-animal interactions.