The Plague in the 1600s: Causes, Impact & the Great Plague of London

In the 1600s, "the plague" referred to bubonic plague caused by Yersinia pestis. Transmitted by fleas on black rats. The Great Plague of London (1665–1666) killed ~100,000 (15% of London's population). Symptoms: fever, chills, painful buboes (swollen lymph nodes).

Contributing factors: overcrowding, poor sanitation, no germ theory. Responses: quarantine (ships, households), pest houses, bonfires, herbal remedies, religious processions—largely ineffective.

Consequences: trade disruption, economic collapse, social inequality exacerbation, cultural legacy (Defoe's Journal of the Plague Year). Later, improved sanitation, quarantine systems, and antibiotics (20th century) controlled plague.