The Great Plague 1665

The Great Plague of 1665 was the last major outbreak of bubonic plague in England. It killed an estimated 100,000 people in London alone — roughly a quarter of the city's population. This lesson covers the causes, spread, impact, and responses to the plague, as well as its significance in the context of Restoration England.

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Background: Plague in Early Modern England

Plague was not new to England in 1665. There had been outbreaks in 1603, 1625, and 1636, as well as regular smaller outbreaks. However, the 1665 epidemic was the most devastating since the Black Death of 1348–49.

The plague was caused by the bacterium Yersinia pestis, transmitted by fleas carried on black rats. However, people in 1665 did not understand this. They attributed the plague to various causes:

Believed Cause	Explanation
God's punishment	Many believed the plague was divine retribution for sin
Bad air (miasma)	The idea that foul-smelling air caused disease
Planetary alignment	Some blamed the conjunction of Jupiter and Saturn
Foreigners and the poor	Immigrants and the impoverished were sometimes blamed