Beyond faith: Biomolecular evidence for changing urban economies in multi‐faith medieval Portugal

Objectives During the Middle Ages, Portugal witnessed unprecedented socioeconomic and religious changes under transitioning political rule. The implications of changing ruling powers for urban food systems individual diets in medieval is poorly understood. This study aimed to elucidate dietary impact Islamic Christian conquests. Materials Methods Radiocarbon dating, peptide mass fingerprinting (ZooMS) stable isotope analysis (δ13C, δ15N) animal (n = 59) human skeletal remains 205) from Muslim burials were used characterize diet a large historical sample Portugal. A Bayesian mixing model (BSIMM) was estimate contribution marine protein diet. Results Early (8–12th century), preconquest populations had mean (±1SD) values −18.8 ± 0.4 ‰ δ13C 10.4 1 δ15N, indicating predominantly terrestrial diet, while late (12–14th century) postconquest showed greater reliance on resources with −17.9 1.3‰ 11.1 1.1‰ δ15N. BSIMM estimation supported significant increase Discussion results provide first biomolecular evidence revolution that not evidenced contemporaneous accounts. We find society transitioned largely agro-pastoral economy rule one characterized by new focus later economic change led naissance went early-modern period its global expansion.