Plague Patterns in Fifteenth Century Milan

From Sforza-era Milan, spanning the late fifteenth and early sixteenth centuries, we have evidence about plague mortality that permits outbreak-mapping of late medieval plagues. A surviving series of urban death registers can be used to compare geographical patterns of early plague epidemics in the city and its suburbs over a seventy-year period. Cause-of-death reporting was a standard component of all state-collected death reports during this era, in every year and for every individual over the age of two years at death. Thus another crucial component of re-mapping plague experience--the comparison of patterns in a plague outbreak to the geography of non-plague epidemics--further distinguishes patterns of plague spread in a larger metropolitan area. Plague deaths were identified by university-trained physicians and surgeons working for a permanent state bureaucracy, and in the long intervals before plague was the established, undisputed reigning epidemic these practitioners inspected the disrobed cadavers for specific evidence of plague lesions. The data that these records provide is as reliable as late medieval human-generated evidence can get.

Using a database of more than 140,000 individual death reports, this presentation will compare the early spread of plague in the city in five early plague years, mapping the spread of the epidemic within the urban and periurban spaces. The geographical patterns of plague spread will also be compared to epidemics that were decidedly not plague-caused, according to the health office authorities. Maps used in this presentation will be historical street and parish-localizing maps rather than GIS, though it is understood that re-mapping the Black Death will in the future require comparisons with the best available evidence, as well as new computerized mapping tools.  The new question put to the present database will be whether plague at the local, urban level, has an early geographical "profile" as a serial killer.