Death on Two Legs: Analyzing the initial 20 weeks of the 1636 London plague outbreak using time-to-event analysis. During the seventeenth century, England experienced multiple plague outbreaks. Although milder than the 1603 and 1624 plague crisis, London’s outbreak of 1636 claimed the lives of roughly 10,400 individuals, approximately 7.5% of the population in London and its liberties.¹ In this blog post, I delve into the first stages of the 1636 outbreak, by scrutinizing the propagation of the plague through London’s city subdivisions, with the aid of time-to-event analysis. The results suggest that, although all parish groups encountered at least one case of the plague in the initial two weeks of the outbreak, the propagation of the plague in the parishes within the walls of London came to a relative halt. In contrast, the outbreak’s trajectory became significantly steeper in the remaining parts of the city, namely the parishes without the walls, the parishes in Middlesex and Surrey, and the outer parishes of Westminster. The analysis aligns with existing literature that highlights a prevalent spatial pattern for plague outbreaks in the seventeenth century: specifically, a milder impact within the city walls and harsher consequences in London’s peripheral areas.² This spatial pattern can be attributed to a combination of factors, including stricter public health strategies–quarantines and isolation–implemented by the city government in the late sixteenth century, as well as the sociodemographic characteristics of early modern London. Furthermore, the analysis unveils that the implementation of containment measures led to a spatially differentiated trajectory of the outbreak: early plague deaths within the walls of London didn’t amount to a propagation of the plague with the same speed as the parts of the city outside the walls.