The Black Death Kills a Third of Europe in Four Years
Genoese trading ships carry Yersinia pestis from a besieged Crimean port to Sicily in 1347, and the disease reaches every corner of Europe within three years
Quick facts
- Pathogen
- Yersinia pestis, bubonic and pneumonic forms
- Also known as
- The Second Plague Pandemic
- Duration
- 1347 to 1351 in its first wave
- Estimated toll
- 25 to 30 million dead in Europe, 30-50% of the population in affected regions
- Entry point
- Messina, Sicily, October 1347, via Genoese ships from Caffa
What happened
The Black Death began in Central Asia and reached Europe in October 1347, when Genoese ships fleeing the besieged Black Sea port of Caffa docked at Messina, Sicily, carrying Yersinia pestis-infected fleas on the black rats that traveled aboard merchant vessels. Within three years the disease had spread to nearly every part of the continent, moving through both the bubonic form, marked by swollen, blackened lymph nodes in the groin and armpits, and the more lethal pneumonic form that spread person to person through the air. Contemporary chroniclers describe fever, joint pain, and death within days in untreated cases; the disease killed an estimated 25 to 30 million people in Europe, between 30 and 50 percent of the population in the hardest-hit regions, and Europe's population did not recover to its pre-1347 level until around 1550.
Why it matters
This is the Second Plague Pandemic, caused by the same bacterium confirmed by ancient DNA in the earlier Plague of Justinian, and it recurred in smaller waves across Europe for the next four hundred years. The scale of mortality collapsed the medieval labor supply, driving up wages for surviving peasants and hastening the end of the manorial system in parts of Western Europe, a social shift historians treat as one of the plague's lasting effects alongside the immediate death toll.
How we know
Contemporary chronicles from Italy, France, and England describe the outbreak's course and toll, and modern historians corroborate the pathogen through ancient DNA studies, including a molecular identification by suicide PCR of Yersinia pestis in medieval burial remains, that confirm the bacterium first identified in 1894 was also responsible for the medieval pandemic.
Sources
- World History Encyclopedia. Black Death · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- PMC (National Library of Medicine). Molecular identification by "suicide PCR" of Yersinia pestis as the agent of Medieval Black Death · Peer-reviewed (author-declared)pmc.ncbi.nlm.nih.gov · Cited as a "journal" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
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Related timelines
- The Middle Ages → · See how the plague's mortality reshaped labor, wages, and the manorial economy across the rest of the medieval period.