In the premodern period, grain crises and epidemics account for the majority of the mortality peaks, certainly when these crises overlapped. Research on the interaction between grain crises and epidemics failed to identify a general chronological or causal link. Especially the impact of epidemics on food crises remains poorly understood. Grain crises in the late Middle Ages were rarely just a question of production disturbances, as they were highly dependent also on trade and the organization of markets. My PhD research identified a higher degree of market integration during price spikes in late medieval Flanders, indicating a generalization of local supply problems over larger regions. The organization and level of integration of grain markets thus seem crucial variables to explain the dynamics between plague episodes and grain crises. This project will test the hypothesis that in an integrated market, price spikes induced by a major epidemic were more evenly distributed across a wider region. In contrast, a similar shock would induce much extremer, but more isolated, price spikes in regions with more fragmented markets. Through the study of late medieval accounts of urban landlords and governments in two regions, the County of Flanders and the city of Toulouse, which were organised differently both politically and economically, I will reveal the link between the degree of (inter)regional market integration and the impact of an epidemic outbreak on food supplies.