1346–1353 · Yersinia pestis

The Black Death

75 to 200 million dead across Eurasia in seven years — the deadliest pandemic ever recorded by share of population. A complete history of where it came from, how it spread, and what we now know happened.

Short answer

The Black Death killed an estimated 75 to 200 million people between 1346 and 1353 — roughly 30 to 60% of Europe's population. It was caused by the bacterium Yersinia pestis, transmitted by fleas on black rats and (in its pneumonic form) by airborne droplets between humans. It originated in Central Asia in the 1330s and reached Europe via the Silk Road and the Crimea.

The death toll

75–200M

Total deaths (Eurasia)

30–60%

Europe's population

7 years

Peak phase

≈ 1 in 3

Europeans died

The estimates have wide ranges because medieval record-keeping was patchy and the bacterium killed entire communities before anything could be written down. Modern demographic modelling (Benedictow 2004, Spyrou et al. 2022) converges on ~50 million deaths in Europe alone and a similar number across the Middle East, North Africa and Asia.

Where it came from

Until 2022, the geographic origin of the pandemic was disputed. That year, a multi-institution team led by Maria Spyrou published ancient-DNA analysis of skeletons from two cemeteries in the Tian Shan foothills of Kyrgyzstan, dated 1338–1339. The genomes contained the ancestor of every later Yersinia pestis strain — the "Big Bang" from which all medieval and modern plague descends.

From Central Asia the disease moved west along Silk Road caravan routes. By October 1346 it had reached the Genoese trading colony at Caffa on the Black Sea. Mongol forces besieging the city — themselves infected — were said to have catapulted plague corpses over the walls in one of the earliest documented uses of biological warfare. Genoese galleys fleeing the siege carried the disease to Messina, Sicily, and from there to the rest of Mediterranean Europe.

Timeline of the pandemic

Year	Event
1331–1334	First plague outbreaks recorded in Yuan-dynasty China (Hopei, Shanxi).
Oct 1346	Pestilence reaches the Crimean port of Caffa (now Feodosia).
1347	Genoese ships carry the disease to Messina, Sicily. From there to Marseille and Genoa within weeks.
Jun 1348	Black Death reaches Paris; mortality 800/day at peak.
Nov 1348	London hit. Up to 60,000 dead by spring 1349 — half the city.
1349	Reaches Norway via a ghost ship at Bergen; Iceland and Greenland follow within months.
1350	Sweden and northern Germany. Norwegian population drops ~50%.
1351	Reaches Moscow. Russian principalities lose ~25% of population.
1353	European phase ends. Outbreaks continue in waves for the next 300 years.
1665–1666	Last major European epidemic: the Great Plague of London (~100,000 deaths).
1894	Alexandre Yersin identifies Yersinia pestis in Hong Kong during the third plague pandemic.
2011	Ancient-DNA analysis confirms Y. pestis in 14th-century London graves.
2022	Gravesites in Kyrgyzstan dated 1338–1339 confirmed as the pandemic's origin.

The pathogen

Yersinia pestis is a gram-negative, rod-shaped bacterium first isolated by Alexandre Yersin in 1894 during the Hong Kong plague outbreak. It has three clinical forms:

Bubonic plague — flea bite → swollen lymph nodes ("buboes"), fever, gangrene. 30–75% mortality untreated. Most common medieval form.
Pneumonic plague — lung infection, airborne transmission between humans. Near-100% mortality within 2–3 days untreated. The fast-killing form that powered the 14th-century outbreak.
Septicemic plague — bloodstream infection, blackening of fingers and toes (origin of the name "Black" Death). Universally fatal untreated.

The bacterium still exists. Modern antibiotics — gentamicin, ciprofloxacin, doxycycline — are highly effective when treatment begins within 24 hours. Without treatment, mortality remains close to medieval levels.

Social aftermath

The pandemic broke the feudal economic order across western Europe. With a third of the labour force gone, the surviving peasants discovered they had bargaining power for the first time. Real wages rose 30–100% over the following decades. Attempts to legally cap wages (England's 1351 Statute of Labourers) largely failed. Within two generations the manorial system was effectively dead.

The Church's authority took a permanent blow. Clergy died at higher rates than the general population (they administered to the sick), and the visible failure of prayer, processions and relics to stop the disease pushed many survivors toward private devotion, mysticism, and later the Reformation.

Persecution of Jews, lepers and other minorities accelerated. The 1348 Strasbourg massacre — in which roughly 2,000 Jews were burned alive on a single day — was one of dozens of pogroms blaming the disease on well-poisoning conspiracies. Art took a macabre turn: the Danse Macabre, memento-mori imagery, the "triumph of Death" motif.

Frequently asked questions

How many people died in the Black Death?

Modern estimates put the Black Death death toll at 75 to 200 million people across Eurasia and North Africa between 1346 and 1353 — roughly 30 to 60% of Europe's pre-plague population. It remains the deadliest single pandemic event ever documented in absolute population share, though COVID-19 has surpassed it in raw deaths.

What caused the Black Death?

The Black Death was caused by the bacterium Yersinia pestis, confirmed by 21st-century DNA analysis of victims' remains. The bacterium was carried by fleas living on black rats; humans became infected through flea bites (bubonic plague) or by inhaling droplets from infected lungs (pneumonic plague). The pneumonic form transmitted person-to-person and is what made the outbreak spread so fast.

When did the Black Death start and end?

The pandemic's European phase ran from 1346 to 1353. It first appeared on the Crimean coast in October 1346, reached Constantinople in summer 1347, Marseille and Genoa by autumn 1347, Paris by June 1348, London by November 1348, and Scandinavia and Russia by 1351. Local outbreaks continued for centuries — the last major European epidemic was the 1665–1666 Great Plague of London.

Where did the Black Death come from?

The strain that caused the European pandemic originated in the Tian Shan mountains of present-day Kyrgyzstan in the 1330s, confirmed in 2022 by ancient-DNA studies of medieval gravesites. From Central Asia it spread west along the Silk Road, reached the Crimea by 1346, and from there spread by ship around the Mediterranean.

How did people survive the Black Death?

Survival mostly came down to luck. There was no effective medical treatment. People who fled crowded cities for the countryside fared better. A small fraction of the European population carries the CCR5-Δ32 gene variant, which research published in 2022 linked to enhanced survival against Yersinia pestis — the strongest natural-selection event ever measured in humans. The bacterium also varies in lethality, and pneumonic plague had near-100% mortality untreated, while bubonic was 30–75%.

Can the Black Death happen again?

Yersinia pestis still exists. The CDC records about 1,000 to 2,000 human cases per year worldwide, mostly bubonic, mostly in Madagascar, the Democratic Republic of Congo and Peru. The United States averages around 7 cases per year, mainly in the rural Southwest. Modern antibiotics (gentamicin, doxycycline) are highly effective when treatment starts within 24 hours. A pandemic at medieval scale is essentially impossible given current public-health systems — but small outbreaks happen every year.

What was the social impact of the Black Death?

The labour shortage that followed the pandemic broke the feudal economic order across Europe. Peasants — who suddenly had bargaining power — saw real wages rise 30–100% in the following decades. The Church's authority was permanently damaged by its inability to explain or stop the disease. Persecutions of Jews and other minorities exploded. Art shifted toward macabre themes (the Danse Macabre). Many historians mark the Black Death as the end of the medieval period.

How does the Black Death compare to COVID-19?

Mortality rate: Black Death untreated was 30–75% (bubonic) or near-100% (pneumonic); COVID-19 case-fatality rate hovered around 0.5–2% depending on age and variant. Absolute deaths: COVID-19 has officially passed 7 million, with WHO excess-mortality estimates between 15 and 20 million — surpassing the Black Death in raw numbers. Population share: the Black Death killed roughly 1 in 3 people in its region in 7 years; COVID-19 killed roughly 1 in 400 globally over 3 years. By every share-of-population metric the Black Death remains incomparably deadlier.

Tool

DeathVault home — interactive map

Database

All historical events

Tool

Compare pandemics side by side

Data

Aggregate death statistics