The Great Plague of London, lasting from 1665 to 1666, was the most recent major epidemic of the bubonic plague to occur in England. It happened within the centuries-long Second Pandemic, a period of intermittent bubonic plague epidemics that originated in Central Asia in 1331 (the first year of the Black Death), and included related diseases such as pneumonic plague and septicemic plague, which lasted until 1750.[1]
The Great Plague killed an estimated 100,000 people—almost a quarter of London's population—in 18 months.[2][3] The plague was caused by the Yersinia pestisbacterium,[4] which is usually transmitted to a human by the bite of a flea or louse.[5]
The 1665–66 epidemic was on a much smaller scale than the earlier Black Death pandemic. It became known afterwards as the "great" plague mainly because it was the last widespread outbreak of bubonic plague in England during the 400-year Second Pandemic.[6][7]