The Plague Years: Five Centuries of Plague Outbreaks in Europe and the Mediterranean, 1347 to 1900, from a Digitised Copy of Biraben's Inventory

Plague reached the Mediterranean in 1347 and returned to European towns for more than three centuries. I describe that history using the digitisation by Büntgen et al. (2012) of the inventory of plague outbreaks compiled by Biraben (1975 to 1976). After repairing faults in the published file (swapped latitude and longitude, a broken row, a missing-value code, repeated rows and five mislocated towns), the data hold 6,848 town-years with plague recorded in 1,172 towns, from 1347 to 1900. The first wave reached 195 towns between 1347 and 1353; a line fitted through distance and first year gives a spread of 176 to 214 km a year as the crow flies, an average over fast sea passages and slower overland spread that annual dates cannot resolve further. Outbreaks peak in the 1630s (570 town-years). The median gap between successive plague episodes in a town is 13 years (interquartile range 6 to 31). Measured by the last year with plague in three or more towns, plague left Italy (1657) and Britain and Ireland (1667) first and France by 1722, but persisted in North Africa to 1821 and in Anatolia, the Levant and Egypt to 1834. The inventory is a record of surviving documents: France alone holds 40% of all records, eastern Europe is thin and Moscow and Constantinople are absent. The results describe the record of plague, not its full extent or its mortality. Interactive version: https://maps.tristanhotham.com/plague-map/. Data and code: https://github.com/Tristan-Hotham/plague-map. Blog post: https://blog.tristanhotham.com/2026/10/31/plague-map/. Licences: the paper is CC BY 4.0. The derived data tables in the zip (data/) are a derived database of the EnviDat dataset doi:10.16904/envidat.181 and are released under the Open Database Licence 1.0. Code is MIT. I wrote the text, with drafting and editing assistance from Claude (Anthropic), which also helped prepare the analysis code. I reviewed and checked all text and results.