Looking to the North Sea : isotopic and osteological evidence for medieval diet, mobility, and health at Stoke Quay, Ipswich

The North Sea trading emporia of the early medieval period were instrumental in the redevelopment of overseas exchange networks in post-Roman Britain, southern Scandinavia, and Western Europe. These trade centres catalysed the process of urbanisation that intensified throughout the subsequent centuries, giving rise to the social and economic landscape of pre-modern England and Europe. Studying the emporia and their evolution into towns can provide insights into the factors that fuelled urbanisation, and can demonstrate the effect of this phenomenon on human diet, health, and mobility in the medieval period. This thesis approaches issues of medieval urbanisation and its effects through chemical and osteological analyses of skeletal remains from 363 humans and 99 animals from the recently excavated site of Stoke Quay, Ipswich (late 6th-late 15th centuries AD). Through stable carbon, nitrogen, oxygen, and radiogenic strontium isotope analysis, paired with osteological and palaeopathological observations, this research characterises the degree and timing of urbanisation at Ipswich, and its impact on the population buried at Stoke Quay. Specific research questions address the timing and extent of the 'fish event horizon' in England, the effects of urbanisation on health, and the extent of mobility and treatment of foreigners in medieval English towns. The paired isotopic and osteological findings challenge the current view that men were the only early consumers of marine fish, but support the hypothesis that intense marine fish consumption was linked to maritime trades. The results indicate that foreigners were subject to higher rates of violence than locals, and that this violence increased over time along with nonspecific stressors and infectious disease. This thesis demonstrates that Ipswich was an exceptional location from the outset, with significantly higher and more widespread consumption of marine resources than contemporary sites across England and around the North Sea, and with a more diverse and dynamic population than was previously imagined.