This causation covers Why Did the Great Plague Kill 100,000 Londoners Despite 300 Years of Medical "Progress"? within The Great Plague for GCSE History. Revise The Great Plague in Medicine Through Time for GCSE History with 8 exam-style questions and 5 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 5 of 13 in this topic. Use this causation to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 5 of 13
Practice
8 questions
Recall
5 flashcards
⛓️ Why Did the Great Plague Kill 100,000 Londoners Despite 300 Years of Medical "Progress"?
Between 1348 and 1665, medicine had seen Vesalius (1543) and Harvey (1628) — yet the Great Plague revealed that medical ideas about the cause of disease had barely changed at all. Understanding why requires examining what had and had not changed since the Black Death.
The real cause was still unknown — The Great Plague, like the Black Death, was caused by the bacterium Yersinia pestis spread by fleas on rats. In 1665, this was still 200 years before germ theory (Pasteur, 1861). Neither Vesalius's anatomy nor Harvey's circulation had said anything about what caused infectious disease — they had improved knowledge of the body's structure and function, but not of the micro-organisms that attacked it. The tools to discover the real cause (powerful microscopes, bacterial culture techniques) did not exist yet.
Wrong theory = wrong response (still) — Because Londoners still believed miasma caused plague, they lit bonfires in streets to "purify the air," carried posies, and burned aromatic herbs. The Lord Mayor ordered the killing of dogs and cats — the wrong animals. Killing cats and dogs removed natural predators of rats, potentially allowing the rat population (the actual disease vector) to increase. This is the same pattern as 1348: a wrong theory produced wrong responses, and the wrong responses sometimes made things worse.
What genuinely changed: organised government response — The 1665 government response was more systematic than anything attempted in 1348. The Mayor of London issued plague orders: infected houses were locked with red crosses for 40 days, watchmen enforced quarantine, the sick were not permitted to leave. Bills of Mortality — weekly counts of deaths parish by parish — were published, creating the first systematic disease surveillance in English history. Searchers (typically old women) were employed to examine bodies and record causes of death. These measures represented a significant expansion of government responsibility for public health, even though they were based on the wrong theory.
Quarantine worked again — for the wrong reasons — As in 1348, quarantine was the most effective measure — not because it prevented miasma, but because it prevented infected fleas from moving from house to house. Houses locked for 40 days meant infected rats and fleas could not spread to neighbouring properties. The 1665 quarantine was more consistently enforced than 1348 attempts, which helps explain why the Great Plague's death toll (100,000 in London, roughly 15-20% of the city) was lower proportionally than the Black Death (30-50% nationally). But the benefit was still accidental — no one understood why quarantine worked.
= The significance: government as public health actor — The Great Plague's most important long-term legacy was not medical but political. The 1665 government response — systematic quarantine, death records, public health orders — established a precedent that government had a responsibility to manage infectious disease. This prefigured the much larger government interventions of the 19th century (Public Health Acts 1848 and 1875) and 20th century (NHS, 1948). The pattern: each epidemic reveals the limits of individual action and forces governments to take collective responsibility.
Quick Check: Give two ways in which the government's response to the Great Plague of 1665 was more organised than the response to the Black Death of 1348.
1. Bills of Mortality: The London government published weekly death counts organised by parish — the first systematic disease tracking in English history. This allowed authorities to monitor the spread of plague across different parts of the city and identify the worst-affected areas. Nothing equivalent existed in 1348. 2. Systematic quarantine enforcement: In 1665 the Mayor of London issued formal plague orders requiring infected houses to be locked for 40 days with a red cross painted on the door and a watchman posted to prevent anyone leaving. In 1348 quarantine was applied inconsistently and locally (notably in Milan) rather than as an organised national or city-wide policy. The 1665 response represented a significant expansion of government responsibility for public health, even though it was still based on the wrong understanding of how plague spread.
Keep building this topic
Read this section alongside the surrounding pages in The Great Plague. That gives you the full topic sequence instead of a single isolated revision point.
Approximately how many people died in the Great Plague in London in 1665?
A. 10,000
B. 100,000
C. 500,000
D. 2 million
1 markfoundation
What were Bills of Mortality introduced during the Great Plague of 1665?
A. Laws banning public gatherings
B. Fines imposed on households that broke quarantine
C. Weekly published counts of deaths from plague
D. Orders to kill dogs and cats in infected areas
1 markfoundation
Quick Recall Flashcards
What were the Plague Orders?
Government rules during the Great Plague: infected houses marked with a red cross, residents locked inside for 40 days, watchmen posted to enforce quarantine
What were Bills of Mortality?
Weekly death counts published by the government — first systematic disease tracking
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