The Black Death in 1348: Beliefs, Facts and the Birth of Quarantine
▶ Play free nowNo install · phone or PC · 3–4 minutes a runThe Black Death reached Florence in the spring of 1348 and raged through the summer. Many historians estimate that more than half of the city died, though the numbers vary between sources. People did what their age believed — incense, bloodletting, processions. Some of what saved lives, like fleeing early and keeping away from the sick, they found by experience. Here is what we know now.
1. What caused it
- Plague is caused by the bacterium Yersinia pestis. It is spread mainly by the bites of infected rat fleas. When rats die off in numbers, hungry fleas move to people. (CDC)
- When the infection reaches the lungs (pneumonic plague) it can spread from person to person through coughing. (CDC, MedlinePlus)
- Untreated, plague kills a large share of those infected; today it is treated with antibiotics, and early treatment works well. (WHO, CDC)
2. What they believed in 1348
- Corrupt air (miasma): physicians told people to shut windows and burn incense and herbs. Smell stops neither fleas nor bacteria.
- Bloodletting: used from antiquity to the 19th century; it did not help and weakened the sick.
- Processions: Boccaccio wrote that the devout prayed again and again in processions and it did not stop the plague. Crowds spread disease.
- Miracle cures: quacks sold costly “theriac” and gold-dust potions. Nothing worked against the plague then.
- Blame: rumours that “someone poisoned the wells” led to the persecution of innocent people across Europe. Plague was caused by a germ, not by people.
3. What helped
- Leaving early for the less crowded countryside — the young people of Boccaccio's Decameron gather at Santa Maria Novella and leave for a country villa.
- Keeping away from the sick and their belongings: Boccaccio says he saw two pigs nose the rags of a plague victim in the street and die soon after.
- Early public-health rules: on 2 May 1348 nearby Pistoia restricted travel to Pisa and Lucca and limited funerals and mourning gatherings — among the earliest public-health ordinances in Europe.
4. Where the word quarantine comes from
- In 1377 the city of Ragusa (today's Dubrovnik) required people from plague areas to stay apart for 30 days (a trentino). The period was later extended to 40 days — quaranta giorni — which gave us the word quarantine.
- So in 1348 Florence there was no quarantine law yet; a household that shut its doors for forty days would have been ahead of its time.
5. Myths about the Black Death
- Beaked plague-doctor masks are a 17th-century image, about 300 years after 1348.
- Smell and smoke were thought to protect; they did not.
- “It's over” was often said too soon: outbreaks seemed to fade and then flared again.
6. Plague today
- Plague still exists in some regions. Avoid sick or dead rodents and their fleas; never handle dead animals bare-handed; use flea control for pets. (CDC)
- Sudden fever with painful swollen lymph nodes after possible exposure needs prompt medical care — antibiotics work. (CDC, WHO)
- Close contacts of pneumonic plague patients are given preventive antibiotics and monitored. (MedlinePlus)
7. Lessons for any epidemic
- Remove what carries the disease (rats and fleas then; mosquitoes, contaminated water or droplets today).
- Keep distance from the sick, care for them safely, avoid crowds.
- Check official information instead of rumours, and never blame a group of people.
Try it in the game: Black Death survival game guide.
FAQ
What caused the Black Death?
The bacterium Yersinia pestis, spread mainly by infected rat fleas; the pneumonic form also spread person to person by coughing.
How many people died in Florence in 1348?
Estimates vary. Many historians think more than half of the city's population died in 1348; Boccaccio's figure of 100,000 is considered too high.
Did bloodletting or incense help?
No. Bloodletting weakened patients, and incense did nothing against fleas or bacteria.
Where does the word quarantine come from?
From Italian quaranta giorni, “forty days”. Ragusa (Dubrovnik) introduced a 30-day isolation in 1377, later extended to 40 days.
Did plague doctors wear beak masks in the Black Death?
No. That costume is first recorded in the 17th century, about 300 years later.
Is plague still around today?
Yes, in some parts of the world, but it is treatable with antibiotics if caught early. Avoid rodents and their fleas and see a doctor for sudden fever with swollen glands.
What were the Pistoia ordinances?
Health rules issued by Pistoia on 2 May 1348 that restricted travel to plague-hit Pisa and Lucca and limited funerals — among Europe's earliest public-health laws.
Is this article medical advice?
No. It is an educational article based on historical records and public-health sources. For any illness, see a doctor and follow official health guidance.