The Black Death: KS3 History Explained

The Black Death was a devastating epidemic that reached England in 1348 and killed between a third and a half of the population. It was caused by the bacterium Yersinia pestis, spread through flea bites, though medieval people attributed it to divine punishment or bad air — they had no concept of germs.

Where did the Black Death come from?

The plague originated in Central Asia and spread westward along trade routes. It reached the Crimea in 1346, where Mongol forces besieging the Genoese trading port of Kaffa reportedly catapulted plague-infected corpses over the city walls — possibly the first recorded use of biological warfare. Genoese merchants fleeing Kaffa brought the disease to Sicily in October 1347. From there it spread rapidly across Western Europe.

In England, the plague arrived at the port of Melcombe Regis (modern Weymouth) in Dorset in June 1348. It spread northward through the summer and autumn of 1348 and into 1349, reaching Scotland and Ireland by 1349–1350.

How many people died?

Estimating medieval death tolls is difficult because census records did not exist, but historians use a variety of proxy measures — wills proved in courts, records of clergy vacancies (when a priest died, a new appointment had to be made), and manorial accounts — to piece together the scale of mortality.

The consensus among historians is that the plague killed approximately 30–50% of England's population. England's population before the Black Death was roughly 4–5 million; it did not return to that level until the sixteenth century, more than 150 years later.

Measure | What it tells us
Wills proved in dioceses of Canterbury and York | Surge in 1348–49 indicates mass mortality in those months
Clergy vacancies (institution records) | Vacancy rates of 40–60% recorded in some English dioceses
Manorial accounts (e.g. Winchester Pipe Rolls) | Record sharp falls in rent income as tenants died, fled, or refused to pay
DNA and skeletal analysis (modern archaeology) | Mass graves identified at London's Charterhouse Square confirm rapid, large-scale burial

What did people think caused the Black Death?

Medieval people had no germ theory of disease. Explanations offered at the time fell into three broad categories.

Religious explanations: Many people — including the Church — believed the plague was God's punishment for human sin. The correct response was prayer, fasting, and penance. Groups of people called Flagellants travelled through Europe publicly whipping themselves to demonstrate repentance, though the practice was eventually condemned by the Pope.

Astrological explanations: The Paris Medical Faculty issued an official report in 1348 attributing the plague to a conjunction of Jupiter, Saturn, and Mars in 1345, which was said to have created "pestilential air." This was not superstition in the modern sense: astrology was considered a legitimate science in the medieval university curriculum.

Miasma theory: Many physicians believed that disease spread through corrupted or "bad" air (miasma), produced by rotting matter, swamps, or celestial events. The miasma theory had practical consequences: people burned strong-smelling herbs, carried posies of flowers, and avoided marshy areas — none of which helped against plague, but the theory was the best available framework for understanding disease until the development of germ theory in the nineteenth century.

Scapegoating: In mainland Europe (though less so in England), Jewish communities were blamed for the plague and faced horrific persecution and massacres, particularly in the Rhineland. The accusation — that Jews had poisoned wells — was entirely unfounded. Pope Clement VI issued papal bulls condemning the violence, pointing out that Jews were also dying of the plague.

What were the immediate consequences?

The speed and scale of death disrupted every aspect of medieval life. Labour shortages created by the death of so many serfs and labourers began to shift the economic balance between lords and peasants.

Bodies piled up faster than they could be buried in consecrated ground; mass graves were dug outside town walls.

Many villages were entirely abandoned. Archaeological surveys have identified over 3,000 "deserted medieval villages" in England, many depopulated by plague.

The Church lost an enormous number of clergy; replacements were sometimes inadequately trained, undermining the institution's prestige.

Some towns and regions attempted quarantine measures: Venice introduced a 40-day isolation period (quarantino, from which the word "quarantine" derives) for ships arriving from plague-affected areas.

What were the longer-term consequences for medieval England?

The Black Death's long-term consequences were profound and, from the perspective of ordinary people, sometimes beneficial — though driven by catastrophe.

Labour shortages and peasant power: With so many workers dead, landowners struggled to find people to cultivate their fields. Surviving peasants could demand higher wages. Lords who refused saw their labourers simply move elsewhere. Parliament passed the Statute of Labourers (1351) to fix wages at pre-plague levels — a measure deeply resented by workers and widely evaded. The tensions this created contributed to the Peasants' Revolt of 1381.

Decline of serfdom: Before the Black Death, most English peasants were villeins, legally bound to their lord's land. After the Black Death, the combination of labour shortages and peasant assertiveness accelerated the gradual erosion of serfdom. By the early fifteenth century, personal serfdom had largely disappeared in England.

The wool trade and enclosures: With fewer people to cultivate fields, some landowners found it more profitable to convert arable land to sheep pasture. Sheep needed fewer workers than arable farming. This contributed to the growth of England's wool and cloth trade — significant for the later development of the English economy.

Frequently asked questions

What were the symptoms of the Black Death?

Historians and scientists now identify two main forms of the plague. Bubonic plague — the most common form — produced swellings called "buboes" in the lymph nodes of the armpits, groin, and neck, often accompanied by fever, chills, and delirium. Without treatment it was fatal in roughly 30–60% of cases within a week. Pneumonic plague (affecting the lungs) was spread through the air and was almost invariably fatal. Septicaemic plague, affecting the blood, was fatal even more rapidly. Most victims in the 1348–49 epidemic died within days of the first symptoms appearing.

Did the Black Death happen only once?

No. The outbreak of 1348–50 was the most destructive, but plague returned repeatedly throughout the later medieval period. Major outbreaks struck England in 1361 (the so-called "Pestis Secunda"), 1369, 1374–75, and at intervals throughout the fifteenth century. London was affected by plague outbreaks well into the seventeenth century — the Great Plague of 1665 was the last major outbreak in England, killing perhaps 100,000 Londoners. The disease was only fully explained when Alexandre Yersin identified the bacterium Yersinia pestis in 1894.

How do historians know so much about the Black Death if there were no surveys?

Historians use a range of documentary and material sources. Ecclesiastical records (documents produced by the Church) are particularly valuable: bishops recorded every appointment and vacancy when a clergyman died, giving historians a quantifiable measure of mortality across different dioceses. Manorial records — accounts kept by lords of their estates — record changes in rent, labour, and land use. Wills give evidence of changing property patterns. Modern archaeology, including DNA analysis of mass grave burials, has confirmed the identification of Yersinia pestis and helped map the spread of the disease across England.

How does the Black Death relate to the Peasants' Revolt of 1381?

The connection is direct. The Black Death created a labour shortage that gave peasants economic leverage they had not previously possessed. When Parliament responded with the Statute of Labourers (1351) to prevent peasants from benefiting from higher wages, this was deeply resented. Over the following decades, resentment of unfair taxation (particularly a poll tax introduced in 1377), continued exploitation by lords, and frustration at legal restrictions on peasant freedom built towards the Peasants' Revolt of 1381, in which rebels from Essex and Kent marched on London. The Black Death did not cause the revolt directly, but it set the conditions for it.

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