This paper reports the results of stable isotopic analyses conducted upon animal and human bones recovered from Yarnton, Oxfordshire. Spanning the Neolithic to Saxon periods, it is in many ways a typical site, but is unusual in that a small Middle Iron Age cemetery was discovered.

All of the data presented here lie within the expected isotopic ranges for the European Holocene, although both faunal and animal δ15N values are higher than is commonly found. The faunal data show the expected pattern for the animals studied (horse, cattle, sheep/goat, pig and dog), with pigs being more omnivorous than ruminants, and dogs eating an isotopically similar diet to humans. The animals' diets had higher δ15N values during the Roman period as compared to the Iron Age, although it is unclear if this reflects an environmental change or alteration in animal management practices. Despite the site's riverine location, there is no isotopic evidence for fish consumption. No distinctions were found based on gender or burial position within the Iron Age cemetery. Age-based distinctions were found in δ13C values, although these cannot be fully explained. As expected, infants have a higher nitrogen isotopic value than other individuals, reflecting the consumption of their mother's milk.