In Rouen, as in many other major European cities, following the Black Death (1347–50) there was increased anxiety about environmental health, and it was thought necessary to protect the urban population from the spread of disease through corrupt, or miasmatic, air. These preoccupations were linked to growing concerns about cleanliness, stench, ‘infection’ and the elimination of ‘pollution’, as a result of which certain features of civic life appeared particularly dangerous, including vagrant pigs and poultry, open latrines, the slaughter of animals in public places, rotten food, rubbish and contaminated water. Such anxieties were closely linked to the Galenic model of human health and physiology as disseminated in regimina sanitatis, the health manuals that were becoming increasingly popular in the later Middle Ages. In theory at least, these regimina were addressed to the upper echelons of society, as reflected, for example, by their advice regarding the consumption of expensive foodstuffs. While Galen maintained that good health resulted from the internal balance of the four bodily humours, he also devoted considerable attention to the non-naturals, which were external phenomena and psychological states that could either prevent or cause illness. They included the quality of the environment, food and drink, exercise, sleep, the purgation of bodily fluids and emotional wellbeing.