Are you sure you meant the “world”population? Because the Black Death was really a European phenomenon. And did not even affect all of Europe.

Rough estimates of the world population around 1300 AD are in the order of 400 million souls, of which about 70 were in Europe. Assuming that the Black Death caused the death of about 15% of Europeans as some estimate, that’s 10 million deaths, pretty impressive, yet only 2.5% of the world population.

Additionally, many historians now believe that Europe’s population declined because of multiple causes including low agricultural yields due to an obsolete economic system and lack of incentives to production, so the plague was just one of many factors.

In any case, a Wikipedia reference indicates that while there was a steep decline around 1350, by 1400 the total population of Europe was back to its 1300 level and slowly grew from there.

Medieval demography - Wikipedia

You must think the 14th century was about the same as today. There wasn't TVs or radio. You got news from talking to people. Taverns were the source for news in a town because travellers slept there. Even when the plague was petering out, I doubt the public knew that. The plague killed so much of the population, there were not many people left to infect. That is how it ended. The only people still alive were resistant to the plague. There wasn't enough population left to sustain it.

There wasn't much understanding of disease. Evil spirits were blamed for sickness. The custom of blessing someone who sneezed started then. You blessed that person to protect your self not the person who sneezed. People were not quarenteening to slow the infection. They didn't behave differently during the plague or after the plague.

The last Black Plague killed 90% of Europe. It was the biggest factor creating the industrial revolution. The printing press was invented but paper was very expensive. Linens had to be burned or made into paper. This made paper affordable and for the very first time books were printed in quantities never seen before.

All the wealth of Europe was concentrated in just a few people. Survors inherited money from dead family members. They started investing their wealth. There was a huge loss of manpower to make products. They built mills on streams and water ways with the money they inherited. Water power was the first energy harnessed to make products in the industrial revolution.

1. Plague of Justinian—No One Left to Die

Yersinia pestis, formerly pasteurella pestis, was the bacteria responsible for the plague. Here it's seen under optical microscopy X 1000.

Three of the deadliest pandemics in recorded history were caused by a single bacterium, Yersinia pestis, a fatal infection otherwise known as the plague.

The Plague of Justinian arrived in Constantinople, the capital of the Byzantine Empire, in 541 CE. It was carried over the Mediterranean Sea from Egypt, a recently conquered land paying tribute to Emperor Justinian in grain. Plague-ridden fleas hitched a ride on the black rats that snacked on the grain.

The plague decimated Constantinople and spread like wildfire across Europe, Asia, North Africa and Arabia killing an estimated 30 to 50 million people, perhaps half of the world’s population.

“People had no real understanding of how to fight it other than trying to avoid sick people,” says Thomas Mockaitis, a history professor at DePaul University. “As to how the plague ended, the best guess is that the majority of people in a pandemic somehow survive, and those who survive have immunity.”

2. Black Death—The Invention of Quarantine

A couple suffering from the blisters of the Black Death, the bubonic plague that swept through Europe in the Middle Ages.

The plague never really went away, and when it returned 800 years later, it killed with reckless abandon. The Black Death, which hit Europe in 1347, claimed an astonishing 200 million lives in just four years.

As for how to stop the disease, people still had no scientific understanding of contagion, says Mockaitis, but they knew that it had something to do with proximity. That’s why forward-thinking officials in Venetian-controlled port city of Ragusa decided to keep newly arrived sailors in isolation until they could prove they weren’t sick.

At first, sailors were held on their ships for 30 days, which became known in Venetian law as a trentino. As time went on, the Venetians increased the forced isolation to 40 days or a quarantino, the origin of the word quarantine and the start of its practice in the Western world.

3. The Great Plague of London—Sealing Up the Sick

Scenes in the streets of London during the Great Plague of 1665.

London never really caught a break after the Black Death. The plague resurfaced roughly every 20 years from 1348 to 1665—40 outbreaks in 300 years. And with each new plague epidemic, 20 percent of the men, women and children living in the British capital were killed.

By the early 1500s, England imposed the first laws to separate and isolate the sick. Homes stricken by plague were marked with a bale of hay strung to a pole outside. If you had infected family members, you had to carry a white pole when you went out in public. Cats and dogs were believed to carry the disease, so there was a wholesale massacre of hundreds of thousands of animals.

The Great Plague of 1665 was the last and one of the worst of the centuries-long outbreaks, killing 100,000 Londoners in just seven months. All public entertainment was banned and victims were forcibly shut into their homes to prevent the spread of the disease. Red crosses were painted on their doors along with a plea for forgiveness: “Lord have mercy upon us.”

As cruel as it was to shut up the sick in their homes and bury the dead in mass graves, it may have been the only way to bring the last great plague outbreak to an end.

Although I haven’t seen anything written on this subject, I would suspect that, in general, plagues die out because of three reasons: 1) Burnout, 1A) Less Lethality, 2) Human Immunity, and 3) Human adaptation.

Burnout - Think of plagues like a fire: the more fuel a fire has, the more it will burn and continue to spread. Starve that fire, and it will go out. Diseases are very similar. The more people that are in proximity to one another, the more likely a disease will spread. Once a plague kills enough people in the cities, there will be a less dense population and less potential hosts to spread to.

Less lethality - I included this as part of the burnout hypothesis because of its method. All diseases are living organisms. Their goal is to survive, so, it is evolutionarily illogical to kill all your available hosts while killing yourself in the process. I have read that diseases mutate and get less lethal over time. Not sure about the Black Death.

Human Immunity - No disease has a 100% mortality rate. That means that humans will contract the disease, but not die from it. Justinian was one such person who had the plague, but didn’t die from it. The more people are exposed to a disease, the more likely they will become resistant or immune to it, which reduces the spread. People can still carry the disease, though.

Human adaptation - When a disease first appears, people will not know about it until its too late; they how to go about their daily lives. When a disease kills a good amount of people, people will begin to adapt their behavior to the disease. This could mean not going out in public or maintaining better levels of hygiene than they did before. A lot of people died BEFORE governments could get a handle on the situation. Once they did, outbreaks became less severe.

Not sure specifically about about the Black Death, but I’d imagine those are the reasons…

Many.

It broke the back of feudalism, for a start. When Europe was well (or even over) populated, the nobles could afford to return a runaway serf to the noble who owned the land he belonged to. After the first major plague, however, principles had a cost. With fields standing full of crops spoiling for lack of harvesters, no matter how sure you were the “vagabond” at your gate was actually unfree, you would be mightily tempted to hire him anyway. He thus earned the money to leave for a city and survive there for a year and a day. If he did, he was a free man.

It also helped the status of women. The plague struck very randomly. In some villages nine out of ten residents died. But for the survivors, some village positions had to be filled no matter what; the miller, the hayward, the cow-boy and the smith being dead made no difference. If those jobs weren't done the village died. So the smith's unmarriageable daughter suddenly had an alternative to the convent. The dairymaid suddenly claimed the hayward and cow-boy's authority and income. The miller's shrewish mother had better things to do than complain. Everybody noticed that these “dependent” women were doing men's jobs just fine, thank you. The upper class didn't like it, but the lesson stuck.

In some places, it was good for the environment. Marginal lands, not suited to farming, go under the plough because of overpopulation. With the population savagely reduced, those lands were abandoned to nature, and were much the better for it. In some places the plagues prevented degradation of the environment that might otherwise have left entire districts uninhabitable.

Lastly, it changed the church, both for better and for worse. Many of their best died tending the sick, leaving carreerists to climb the ladder. Cowards don't make the best bishops. But it also loosed the stranglehold of doctrine on the common people; if you see a priest only twice a year, you don't fear him much. Thus it helped pave the way for various reforms.

The plagues were horrible. But, as always, they were not unmitigated horrors. If they had never occurred we might still be a viciously patriarchal, priest-ridden culture where far too many were barely one step up from property. I'm happy we aren't.

It basically ran out of hosts.

It killed a third of all Europe. Like all organisms, it did not kill all who contracted it, although in many cases, it got pretty close. There were places that were wiped out (I recall reading about a chronicle of a monastery where the account tells of the monks dying of the plague, and finally the chronicle goes silent, as the last monk has died) , and places where the plague never got to, such as Oberammergau. Eventually the supply of hosts dried up, and that was that — til the next time.

You need cheering up? Well, the fact is, the Plague never went away! It’s still around. Just not virulent. It came to California with the influx of people with the Gold Rush, and then it jumped to the animal population, where it still is a real threat. If you are hunting, there are some precautions you very possibly have been told to take if you are in certain locales. I understand that it is active in some of the big cats in the Western parts of North America, among others.

Nasty business!!

No antibiotics. When someone catches the bubonic plague today, we use antibiotics to kill the bacteria causing it. People in earlier ages had no effective treatment. If you caught the plague, you were at its mercy.

No understanding of the cause. They believed the plague came from miasma, or bad air. In fact the most common variety was carried by fleas that fed on rats. Rats were ubiquitous in medieval life, and fleas were an inescapable pest; women even wore “flea traps” under their clothes to minimize personal infestation. Even if they had understood that fleas spread the plague, there was little they could do to protect themselves.

This 19th century flea trap would have been baited with honey and perhaps blood. Fleas crawled inside and were trapped in a sticky layer

Add all that to a highly infectious bacteria (in three varieties with different transmission vectors) with a high fatality rate, and you get the Black Plague

ADDED: There is an alternative theory of transmission that blames human body lice. Same answer to the question, though.

Why?

In October of 1347, ships pulled into the docks of the port of Messina after a long trip through the Black Sea. There were twelve of them. People lined the docks to see what exotic delights they had returned with—perhaps a new wine or liqueur, or some tasty new spice or beautiful silk—they jostled to see. But what they saw was a horrific surprise: everyone on board those ships was either dead or deathly ill; those few sailors who still lived, would not do so for long. They were overcome with fever, unable to keep food down and delirious from pain. Strangest of all, they were covered in mysterious black boils.

Sicilian authorities hastily ordered the fleet of “death ships” out of the harbor. They had no way of knowing it was already too late. The carriers of the bacillus (Yersina pestis)—the fleas and rats so at home aboard ships of all kinds—were already scurrying ashore.

RATS

The black rat, also called the ‘house rat’ and the ‘ship rat’, likes to live close to people. That is what makes it dangerous (in contrast, the brown or grey rat prefers to keep its distance in sewers and cellars). It slinked ashore, carrying its deadly cargo, infesting local nests of others of its kind with the deadly disease.

FLEAS

Normally, it takes ten to fourteen days for plague to kill off a contaminated host-rat colony. This makes it difficult for the large numbers of fleas gathered on the remaining, but soon-dying rats, to find new hosts. After three days of fasting, hungry rat-fleas turn to humans. Unlike human fleas, rat fleas are adapted to riding with their hosts; they readily infest the clothing of people entering affected houses and ride with them to other houses or localities.

A tiny little flea bite, that’s all it took, and from that bite-site, the contagion would drain to a lymph node that consequently swelled to form a painful bubo, most often in the groin, on the thigh, in an armpit or on the neck. (Hence the name bubonic plague.)

The infection takes three–five days to incubate in people before they fall ill, and another three–five days before, in 80 per cent of the cases, the victims die. That means, from the introduction of plague contagion among rats in a human community it takes, on average, twenty-three days before people begin dying.

SHIPS

Plague spread from port to port. Not long after it struck Messina, the Black Death spread to the port of Marseilles in France and the port of Tunis in North Africa. Then it reached Rome and Florence, two cities at the center of an elaborate web of trade routes. By the middle of 1348, the Black Death had struck Paris, Bordeaux, Lyon and London.

A few years earlier, the disease had struck China, India, Persia, Syria and Egypt, and frightening rumors of it had made their way to Europe. Having no defense, and no understanding of the cause of the pestilence, the men, women and children caught in its onslaught were bewildered and panicked.

TIME

It took some time for people to recognize that a terrible epidemic was breaking out among them and for chroniclers to note this. The timescale varies: in the countryside it took about forty days for realisation to dawn; in most towns with a few thousand inhabitants, six to seven weeks; in the cities with over 10,000 inhabitants, about seven weeks, and in the few metropolises with over 100,000 inhabitants, as much as eight weeks. This gave ample time for it to spread.

Inspired by the Black Death, ‘The Dance of Death’ or ‘Danse Macabre’, an allegory on the universality of death, is a common painting motif in the late medieval period.

PANIC

Historically, Hippolytus and Galen—ancient giants of medicine—advised when dealing with plague: “Cito, Longe, Tarde,’ which translates as ‘Leave quickly, go far away, and come back slowly.” Isolation was all they knew. Doctors refused to see patients; priests refused to administer last rites. Shopkeepers closed stores. Many people fled the cities. Milan avoided an outbreak by sealing up three houses (with the occupants inside) after plague was discovered there. The Black Death and early public health measures

Fugitives from a plague-stricken town or area would arrive in uninfected areas having no idea they carried infected rat-fleas in their clothing or luggage. Plague soon broke out in these urban and rural centres; from there the disease spread into the villages and townships of the surrounding districts by a similar process of leaps. This pattern of spread is called ‘spread by leaps’ or ‘metastatic spread’.

Often, the Black Death rapidly established two or more fronts and conquered countries by advancing from various quarters.

The Italian writer Giovanni Boccaccio lived through the plague as it ravaged the city of Florence in 1348. “The symptoms … began both in men and women with certain swellings in the groin or under the armpit. They grew to the size of a small apple or an egg, more or less, and were vulgarly called tumours. In a short space of time these tumours spread from the two parts named all over the body. Soon after this the symptoms changed and black or purple spots appeared on the arms or thighs or any other part of the body, sometimes a few large ones, sometimes many little ones. These spots were a certain sign of death, just as the original tumour had been and still remained.” The Black Death, 1348

Blood and pus seeped out of these strange swellings, which were followed by a host of other unpleasant symptoms–fever, chills, vomiting, diarrhea, terrible aches and pains–and then, in short order, death.

The Black Death was terrifyingly, indiscriminately contagious: “the mere touching of the clothes,” wrote Boccaccio, “appeared…to communicate the malady to the toucher.” The disease was also terrifyingly efficient. People who were perfectly healthy when they went to bed at night could be dead by morning. The Black Death and early public health measures

IGNORANCE

No one knew exactly how the Black Death was transmitted from one patient to another–according to one doctor, for example, “instantaneous death occurs when the aerial spirit escaping from the eyes of the sick man strikes the healthy person standing near and looking at the sick”–and no one knew how to prevent or treat it.

Physicians relied on crude and unsophisticated techniques such as bloodletting and boil-lancing (practices that were dangerous as well as unsanitary) and superstitious practices such as burning aromatic herbs and bathing in rosewater or vinegar. “Such fear and fanciful notions took possession of the living that almost all of them adopted the same cruel policy, which was entirely to avoid the sick and everything belonging to them. By so doing, each one thought he would secure his own safety.”

It didn’t work.

A Florentine chronicler relates that,

“All the citizens did little else except to carry dead bodies to be buried… At every church they dug deep pits down to the water-table; and thus those who were poor who died during the night were bundled up quickly and thrown into the pit. In the morning when a large number of bodies were found in the pit, they took some earth and shovelled it down on top of them; and later others were placed on top of them and then another layer of earth, just as one makes lasagne with layers of pasta and cheese.”

Remains of mass grave

“In this suffering and misery of our city, the authority of human and divine laws almost disappeared, for, like other men, the ministers and the executors of the laws were all dead or sick or shut up with their families, so that no duties were carried out. Every man was therefore able to do as he pleased.” The Black Death, 1348

Social order broke down.

“So many people had died that there were serious labor shortages all over Europe. This led workers to demand higher wages, but landlords refused those demands. By the end of the 1300s peasant revolts broke out in England, France, Belgium and Italy.”

25 million people died in just under five years between 1347 and 1352. The Black Death: Bubonic Plague

Eventually, fully a third of the population died—entire families were gone—whole villages turned into ghost towns. Medieval Europe—its politics, economics, and religion—would never be the same again.

MODERNIZATION

“The extent of the contagious power of the Black Death has been almost mystifying.” The central explanation lies within those features of medieval society that were particular to its time. It was caught betwixt and between paradigm shifts: with one foot still in the past, there was also a new dynamic: modernization.

In this early phase of modernisation, Europe was unwittingly on the way to ‘the golden age of bacteria’ when there was a great increase in epidemic diseases— caused by increases in population density and in trade and transport—while knowledge of the nature of epidemics, and therefore the ability to organise efficient countermeasures, was still minimal. The Black Death and early public health measures

TRADE

Early industrial and capitalistic developments had advanced. New, larger types of ships carried greater quantities of goods over extensive trade networks. This system for long-distance trade was supplemented by a web of short and medium-distance trade that bound together populations all over the Old World.

The strong increase in population in Europe in the High Middle Ages (1050-1300) meant agriculture ran out of space. So forests were cleared and mountain villages settled wherever it was possible for people to eke out a living. People had to opt for raising or growing one product for market in order to create a surplus that could be traded for staples such as salt and iron, grain or flour. (But if all you raised was sheep, and the sheep all died from plague—you and your family starved.) These settlements operated within a busy trading network running from the coasts to mountain villages. So along with tradesmen and goods, contagious diseases reached even the most remote and isolated hamlets.

Much new can be said on the Black Death’s patterns of territorial spread. Of particular importance was the sudden appearance of the plague over vast distances, due to its rapid transportation by ship. Ships travelled at an average speed of around 40km a day which today seems quite slow. However, this speed meant that the Black Death easily moved 600km in a fortnight by ship: spreading, in contemporary terms, with astonishing speed and unpredictability. By land, the average spread was much slower: up to 2km per day along the busiest highways or roads and about 0.6km per day along secondary lines of communication. Black Death - Facts & Summary - HISTORY.com

Even when the worst was over, smaller outbreaks continued, not just for years, but for centuries. The survivors lived in constant fear of the plague's return, and the disease did not disappear until the 1600s. The Black Death: Bubonic Plague

The Black Death and the Transformation of the West

The single most important and critically overlooked point in the spread of the plague is the semi-starved state of the average medieval person, urban or peasant. Malnutrition makes people **far** more susceptible to disease. I emphasize this because it is crucially important in understanding (and sympathizing with) the health problems and famines in developing nations today. Few malnourished people die of actual starvation: most die of disease.

Recently archeologists in London have analyzed mass graves and discovered many Black Death victims were malnourished migrants from places as far away as Scotland. Many worked in jobs that required backbreaking labor, as revealed by spinal degeneration.

Skeletons buried beneath square were malnourished London victims of Black Death

The poor health of many of those born around the Great Famine (stunted growth, etc), the absurd 100 Years War between England and France, and a cooling climate due to the LIA all contributed to frequent minor famines and food shortages. Meaning the people being squeezed economically by rising prices due to climate change (smaller harvests) would have had even less food and been even weaker. (War leads to food shortages and often famines.)

It is probably no coincidence that the 100 Years War was raging right before the Black Death struck. Nothing like War to usher in the other horsemen of the apocalypse (famine, pestilence/disease)… There’s a reason the ancients grouped these together.

The Black Plague, also known as the Black Death, was one of the deadliest pandemics in human history. It ravaged Europe during the 14th century, leaving a trail of devastation in its wake. While it is challenging to determine an exact number, it is reasonable to estimate that millions of people lost their lives due to this horrific disease.

To provide some context, the Black Plague first emerged in the mid-1300s, originating in Asia and spreading rapidly along trade routes. It reached Europe in 1347 and quickly spread like wildfire, engulfing the continent in a wave of death and despair. The disease was caused by the bacterium Yersinia pestis, which was primarily transmitted through fleas infesting rats.

The impact of the Black Plague on Europe was cataclysmic. Entire communities were decimated, with cities and towns transforming into ghostly remnants of their former selves. The disease struck both rural and urban areas, affecting people from all walks of life, regardless of social status or wealth.

Now, estimating the exact death toll from the Black Plague is a challenging task. Historical records from that time are not entirely reliable, and the methods used to record deaths varied across regions. However, scholars and historians have pieced together available data to form informed estimates.

According to various sources, including documented accounts, church records, and demographic studies, it is believed that the Black Plague claimed the lives of anywhere between 25 to 75 million people in Europe. To put this staggering figure into perspective, the population of the entire continent at the time was around 80 million.

The plague’s impact was so severe that it disrupted societies and economies across Europe. As labor shortages became prevalent, wages skyrocketed, causing significant socio-economic changes. This period marked the beginning of the end for feudalism, as peasants demanded better treatment and higher compensation for their work.

the Black Plague had far-reaching consequences beyond its immediate death toll. The trauma and fear it instilled in people’s minds lingered for generations, shaping cultural, artistic, and religious expressions. The plague’s devastating effects were often depicted in various art forms, serving as a reminder of the fragility of human life.

My information is just from reading one book by Barbara Tuchman called “The Calamitous 14th Century.” There wasa “mini” Cold snap Ice Age if you will (page )that lasted 300 years in Europe, causing closer quarters and less food. Ok, I can't find the page that reflected this. If anyone can, It would be great if you listed it.

The Death went from Iceland down through India, a third of the world.

There were two forms, one that got into the bloodstream and one that was respiratory.

The death rate per day before 1349, was from 800/day in Paris, to 500–600/day in Vienna (Austria.) They put dead bodies for example in the Rhone River, in FR. A doctor would catch it from his patient--and die at that patient's bedside, before the patient died.

People lived closer together as a result of the colder weather, and that caused the bacterium to spread due to proximity: thru fleas which didn't need to live on rats to travel. Women —who stayed inside (closer to fleas) were more suseptible.

Food was not as plentiful due to shortened growing seasons, and there was greater susceptibility to sickness due to people being undernourishd. The bacterium travelled by fleas which didn't need to be on the rats, so travel quickly amongst the filth it did. (Lack of sanitation was another cause.)

People became apathetic, as a matter of fact crazed. They believed it was the end of the world, not being able to see or understand the plague's cause. They were unable to cope with the quick deaths and the number of deaths. They just left their crops un planted and unharvested. Their animals ran wild. In spreadout Dalmatia, wolves attacked survivors. The cattle died, as did dogs and cats.

They believed God was taking vengeance against humankind. People died inside of a 24-hour period after contracting the disease.

The spread is believed to have started in Asia not China, and spread along the caravan routes.

If you mean the Black Plague Outbreak, it started in Asia (probably in the mountains between modern day Kyrgyzstan and China) in about 1337–1338, in Europe it arrived in 1347 in Crimea and expanded from there, then petered off in the early 1350’s. Overall the outbreak lasted for about 15 years, more or less. But it wasn’t present throughout the world at the same time: for instance, in one region plague could rage one year, then expand to the neighboring region, and while in the first region it may already be dying out, the second may have the highest death toll the following year.

If you mean the Second Plague Pandemic, of which the Black Plague was the opening act, it pretty much lasted until the early XIX century, with the last major outbreaks occurring in the Ottoman Empire, in Malta, and in Romania between 1812 and 1819, and a final outbreak in Baghdad in the 1830’s.

Between 1346 and 1353 the second wave of the plague, dubbed the black death, ravaged Europe and killed millions. Up to a third of the population was wiped out (Though that's a rough estimate. We don't really know.)

But it wasn't the first time the plague broke out and it wasn't the last. The plague has been around for centuries and still exist to this day.

The cause of the plague is a bacteria called Yersinia pestis. And like many bacteria, they have different and evolving strands.

In an extremely simplified version, you have to see the plague as something similar to the flu. So what happens during a flue endemic, is that it quickly spreads, everybody susceptible gets sick, create antibodies and fights it off, until there are no more new victims and the virus dies off as it cannot find hosts to replicate itself anymore. And the next year there's gonna be a new strand that will make its rounds. But not every strand it's equally bad. Some strands, like the Spanish and Russian flu, caused millions of deaths.

That's basically what happened with the plague as well: it quickly spread, killed between 75 and 200 million, until there were no more susceptible victims anymore and the plague slowly died.

Other factors, such as quarantine protocols, cold weather killing fleas, rats falling victim to the plague etc. were also a factor.

Those who had cats…

In the long history of human-animals relationships, a few episodes stand out in which one species has made a significant contribution to the survival of another. Rarely do cats get credit for such an accomplishment--more often dogs or horses, and then, usually in times of war--but the Black Plague of Europe is one of those times.

By way of background, the ancient Romans, in their conquest of Egypt, had brought cats home to Europe. Cats subsequently suffered a period of disfavor during the superstitious Middle Ages, for they had become associated with witches and the Devil; some people believed black cats were witches in disguise, or that they assisted witches in performing their craft. Those who kept cats as pets were the objects of much suspicion, and widespread cat hunting led almost to their extinction.

When rats from Asia brought the bubonic plague to Europe via trading ships in the mid-1300s, the epidemic (variously known as the Black Plague, the Great Plague, the Black Death, and the Great Mortality) swept across the continent, resulting in devastating loss of human life. In all, one-third of the population of Europe--some 34 million people--died. In England alone, more than half the human population perished; in some parts of France, ninety percent.

It took the authorities some time to figure out the cause of the problem. At one point they tested the theory that the disease was being spread by dogs and cats; thus the mayor of London ordered the execution of all such pets. Despite the extermination of millions of companion animals, however, the plague did not abate but actually accelerated, for, of course, the elimination of all cats was soon followed by an explosion of the rat population.

Eventually it became evident that people who had kept cats, in violation of the law, fared better; for the cats, according to their nature, killed the rats that carried the fleas that really carried the plague. People slowly began to deduce the rat-flea-disease connection. When the truth finally came to light, cats were quickly elevated to hero status, and soon became protected by law.

The Great Plague ended when the fleas started dying, as a part of their natural life cycle, in the cold of fall and winter. Subsequent plagues would visit Europe over successive generations, and other continents suffered similar outbreaks; it would not be until the 19th century that scientists really began to understand the epidemiology of the plague. Increased sanitary conditions over time helped reduce its incidence, and with the discovery of antibiotics in the 20th century, the threat of the plague was greatly reduced.

Would it be a stretch to say that, by bringing the rodent population under control, cats saved humans from extinction? At least, European humans? At a minimum, cats deserve credit for heroically saving the species that, through ignorance, almost wiped them out.

Cats, People, and the Black Plague - Those Who Kept Cats Survived (ezinearticles.com)

Article Source: http://EzineArticles.com/161249

One general rule is that diseases don’t travel alone. Infectious diseases don’t walk and don’t fly, they are taken around by people who have already been infected and yet are traveling. This is why when a new infectious disease pop us the first measure to adopt is inhibit all traveling, long, medium, and short radius.

The Black Death outbreak was brought around by such travelers. At first by migrant Mongols, then by Chinese, Middle eastern, and European merchants, and finally by people just fleeing the plague where it ha already hit. What happened is that the X city got an outbreak, people saw really bad plague cases and a lot of them (plague wasn’t anything new, while the first plague pandemic had been finished for several centuries, there were still quite a few isolated cases and small outbreaks that sometimes included an occasional septicemic case), got scared and moved away, seeking refuge in a nearby city or town. They always brought with them stories of the horrible disease outbreak, and quite often during the trip one of them got sick and by the time the group reached the Y city they counted one or more sick people in their fold that didn’t only spread voice of the plague but also spread the infection.

So, yes, people knew. The most educated and cosmopolitan had been in the know for quite a time, since news of the disease came in from the east, through the Byzantine Empire. Common people may learn about it later, when the disease started spreading in the vicinity. But people knew that a new and unusually bad form of the plague was spreading fast and killing many. They even knew what the disease was.

In first place, it was the rest of the Second Plague Pandemic. The “Black Death” outbreak lasted around 15 years, starting in the late 1330’s in central Asia and traveling both Westward and Eastward (and later towards southern Africa after it infected the Norther Africa shores). In each area the outbreak lasted only a few months, though.

This was only the first outbreak. The Black Death heralded the much lengthier Second Plague Pandemic that would ravage Europe, Asia, and Africa for 5 centuries, only relenting in the late XVIII century. The following years saw major plague epidemics of regional size occurring yearly. A previous pandemic occurred after the Justinian Plague outbreak and had lasted around 3 centuries, from the VI to the IX, but since that moment plague had become an endemic disease with no epidemics and with milder symptoms.

Not only the very scary Black Death outbreak, which was characterized by the frequency of the extremely deadly septicemic form of plague, but also the subsequent epidemics left a deep impression in the European culture and art. For a couple of centuries, the danse macabre became one of the favorite themes of art.

We also need to not forget that the start of the pandemic coincided with the age of the great Malthusian crises: at regular intervals the European population reached new highs, incompatible with the ongoing agricoltural tech. Combined with the climatic cycles that brought colder weather over Europe and the Mediterranean, this cause massive famines that, in turn, made the epidemics worse.

But that is only the start. The lasting impression caused by the Black Death and the subsequent plague epidemics and Malthusian catastrophes, undermined the trust in the Catholic Church and is probably among the causes of the popularity of the reform. While the predication of the various leaders (Luther, Chauvin, etc.) didn’t have direct ties with the pandemic, its effects created the conditions of deep insecurity. People often turned to religion, and people, deluded by the failure of the Church to protect them from these disasters, turned to the new forms of religion. These combined with the political unrest. Often these new forms of religion collected also the disquiet of the new poor caused by the declining economy during the Malthusian crises and supported religious leaders that also promised equality and the end of the rule of the nobility like Thomas Müntzer. (If you want a fun read about this period, I suggest Luther Blisset’s novel Q.)

Another relevant aftermath is capitalism. Although true capitalism is a much later phenomenon, the process that led to the capital accumulation started as a reaction to the depopulation of the countryside due to the Black Death. That far the land had been owned collectively by whole villages. Each family had a house, a greengarden, and a little orchard, but the major fields and pastures were owned collectively. Each family received from the village elders a section of land proportional to its workforce in each of the Spring and Fall crops fields, a third field was left fallow to allow it to regenerate. The village also owned woodlands and meadows to collect wood and gather mushrooms, herbs, etc. The lord and the local church (sometimes the local lord was a bishop or a monastery, so the two coincided) also owned some of the agricoltural land that was worked by the peasants for a few days a month, these land provided food for the lord and the priest (and their households: don’t forget that priests until the XVI century could have wives and children, although by the XIII century it was rarer and considered in bad taste), and the surplus went in part into paying taxes (common people were exempt from taxes) and in part into constituting emergency stores in case of famine.

This system worked well until the workforce was plentiful and cheap. But with the Black Death many areas of England became depopulated. Progressively, the land stopped being used collectively. Peasants refused to work for free in the lords’ fields and started requiring a salary. The shared lands started being enclosed with fences, hedges, and dry walls. These enclosures movement made the land itself a commodity that could be bought and sold (previously there were a few private landowners, but they were few and far between), richer families started to buy over the land of those who had a hard time, and this created an accumulation of land, which in turn created a new social class, of private, titleless landowners. These landowners, and those nobles that followed the same path, started accumulating capital, which they could invest in more land, better farming equipment, but also in commerces and artisanal endeavours. This is the primitive accumulation Karl Marx talks about in the Chapter XXIV of The Capital. It created the conditions necessary for the future development of capitalism.

Why was the bubonic plague called the Black Death?

You have never seen a case, have you? I saw a picture in a local paper. The plague is carried by several species of the rodent family here in New Mexico and other areas of the world.

Antibiotics prevent the spread of it like it spread in Medieval times.

Turn black and die.

Ore. man survives "black death" plague (GRAPHIC IMAGES)

Pinter Pandai - Gudang Pengetahuan

The New Bio- X20!

Plague has three forms: bubonic, pneumonic, and septicemic.

The septicemic plague is often called “black plague”. It is caused by the bacteria entering the bloodstream and causing blood clots. These clots plug the blood vessel and cause gangrene of the skin, fingers, toes, nose, lips, which turn black. If left untreated, the grangrene causes septicemy (blood poisoning) killing the patient. If left untreated this form of plague kills virtually the 100% of the patients.

Septicemic plague was predominant during the first outbreak of the second plague pandemic, hence the name “Black death”.

Yersinia pestis, the bacterium believed to have been responsible for most of the Black Death, is still around. In the US, prairie dogs are a major reservoir. The disease springs up infrequently in the US, causing about 7 infections in a typical year. In the last 50 years, we’ve had less than 500 cases, almost all in the American west and southwest. 0–2 American deaths due to Plague occur in a typical year.

Central Africa and Madagascar also have cases, and more than the US, but still not enough to make it a common disease.

Y. pestis is vulnerable to several antibiotics and you are far, far less likely to die from it today. Additionally, as we have less fleas and lice today, we are much less likely to transmit it. We are less likely to get it.

It is highly improbable for Y. pestis to ever cause large scale death in our modern world, but I do not think anyone can say it’s impossible. Black Swans happen from time to time.

What were the different types of plagues in the Black Death?

The plague, Black Death, God’s Revenge, or whatever name you choose was the great killer of the Middle Ages. The number of deaths is unknown, only estimated, and that estimation is three million. Compared to Hitler’s Holocaust and its 6 million murdered Jews, three sounds negligible. However, the population was much lower in medieval times and 3 million was a devastating blow to society.

Bubonic was transmitted primarily through fleas. It caused swellings in the lymph glands; the neck, underarms, and groin areas were the most common areas. Opening the buboes to drain was not a common treatment; prayer was. The few who survived had a natural immunity.

Pneumonic wasn’t a silent killer. One of its symptoms was a cough. I believe the custom of saying “Bless you.”, “God bless you” in the appropriate language began then and is still used today without people knowing the history behind it. A Pope (Gregory?) suggested that the blessing be used by the faithful in the hopes they would then be protected from the illness. The droplets sprayed

carried the seeds of death to the unsuspecting. That’s why people are taught to cover the cough or sneeze in their hand, a kleenex, a handkerchief if anyone still carries them. I still have my Mom’s given her by a grateful postal patron. They have fragile lace tatted around the edges. In medieval times people used the long sleeves on their outfits, on the tablecloth, the long hoods worn by the men

—- anything that had handy — or they sprayed the neighborhood.

Septicemic is the most horrific. It involves a brain-boiling fever, abdominal pain,

and leakage of blood from the nose, mouth, or rectum.

This disease is still active in parts of the world — including my New Mexico.

Pinterest pictures

What is the cause of the Black Death plague?

This is what I taught:

A bacterium, Yersinia pestis (image above), arose somewhere in Asia. Fleas carried the disease and spread it freely. It infected rats that carried the

disease from its starting point into the Mediterranean and then into Europe. The rats were likely on ships carrying trade goods. The fleas jumped from the rats to the sailors on the trade ships. When the ships reached a harbour and the sailors went ashore, Europe and millions of people were doomed.

Fleas continued to be the main carriers of the disease, but other animals including humans spread the disease also.

Below is an artist’s vision of the Black Death.

The Triumph of Death by Pieter Bruegel. The image can be viewed in Wikimedia Commons. It is magnificent when zoomed so as to examine the details.

The Black Death cast its shadow across Europe for centuries. It is active today in my home state, New Mexico.

www.genome.gov

Images from the internet.

Yes ,you will find it intresting that 10 percent of european population is immune to HIV ,chicken pox and all the other dieseases that uses CRR5 to enter in human cells and but not to bubonic plague, bubonic plague is different ,it believes that people with these mutation has natural advantage over others they were more resistant so they are more likely to survive black death.

So what is this mutation ?? the mutation of CRR5 into CRR5 delta 32 ( delta32 means deletion of particular 32 base pairs in dna )

CRR delta 32 people are also immune to cerebral malaria ,this also reason that they handle brain damages easily and also they are good with books.

So why dont we have some kind of vaccine to change CRR5 into CRR delta 32 ???It can ,but we dont have it yet ,chinese scientist Hu Jinkawi has use CRISPR CAS9 (dna editing tool) to do so but DNA tempering is illegal in child below 14 days. Other than this CRR5 delta32 can be carried from parent to there babies only if both the parents have there portion of delta32 in them (this is called homozygous ) so you have to be lucky enough.

In the Middle Ages, the plague extinguished the population of entire regions, millions of people died of the black plague. Where does the plague come from?

One theory suggests the origin of the Black Death, the Plague, the Great Death, God’s Punishment, or whatever name you prefer was China. Historians termed the trade route from China to Europe via land the Silk Road.

Silk, manufactured only in China for centuries, was in high demand in Europe. Traders moved it by land and by sea. They bundled silk for the trip, and fleas were uninvited passengers. For travel from China to Byzantium, camels were

the preferred mode.

Some of the earliest reports of the Black Plague, or bubonic plague, show up historical accounts of the 1320s in China, the 1330s in Central Asia, and the 1340s in Europe.

When I taught about the plague, I described three ships arriving in a nameless Sicilian harbour. I spoke of the unsuspecting townspeople, their horror at the sight of the dead, their decision to help themselves to an expensive cargo, and their innocent parts in the disaster to come. I spoke of the agonies of the plague, the bewilderment of the dying Sicilians, and the attempt of some to flee — unaware that they were carrying the cause of the deaths of millions on their persons and in their clothing.

So, China to Sicily and Sicily to virtually every part of Europe. Again, historians debate rat vs. human as the carrier; the vector doesn’t matter. Here is the killer, yserinia pestis.

Images from Pinterest

The Arrival and Spread of the Black Plague in Europe

For all the most famous “rock-star” plagues that decimated great swaths of mankind, it’s important to have an air of mystery, as far as your origins go… it gives a seductive charm to a disease, like, “ooh he’s so mysterious, where did he originate…?”.

The Black Death (or the “Plague”) was no different, and no one can pinpoint exactly where it came from, except from China or Central Asia when trade was going hog-wild.

BUT, we CAN pinpoint a pivotal moment in the Black Death reaching Europe, which would be funny if it weren’t for that whole “murdered 30–60% of Europe’s population” thing…

During the Mongol siege of Genoese traders at Caffa in 1346, the Black Death ravaged the Mongol camps just outside the stronghold where the Genoese were hiding.

The Genoese began to laugh and make plague-related puns at them from atop the walls: “somebody call Youtube! The Mongols are going viral!”

The Mongols became really salty after that, and thought, “why should the Genoese be making all the puns? Let’s give them a taste of their own medicine!”

“Their own medicine” in this case, was a bunch of plague-ravaged dead Mongol bodies, and the “medicine spoon” was a bunch of giant trebuchets!

Trebuchets + plague corpses = ???

Yes! The world’s worst confetti!

I know what you’re probably thinking, “wow, biological warfare? Fashion faux pas, Mongols…”

However, these guys had not yet heard of the 1925 Geneva Protocol (how ignorant, am i right??), so splattering a couple of putrid meaty plague bombs all over the stronghold was “just good business” (-Pirates of the Caribbean 3).

The Genoese eventually escaped the siege, and returned home to Italy, having a grand old time singing sailor songs in between bouts of coughing up blood.

Once the Black Plague reached Italian port cities, the rest, as they say, is history.

In fairness, some scholars disagree that this was the singular event that brought the plague to Europe, and I’m sure those ships were just a few out of dozens carrying plague-ridden fleas in their cargo holds, but who cares. This is a fun story.

~

~

Check out History Muffin on Youtube, which is my special history animation channel! I animated a whole episode I call “How Does the Black Death Kill You?”, and you can watch little puppet people succumb to a rampant bacterial infection.

I worked super hard on it so I hope you love it…

Thanks for reading!

Quickly is a matter of historical perspective. It took seven years, from 1346 to 1353, for the bubonic plague pandemic to spread throughout Europe, North Africa, and West Asia. It is the most fatal pandemic recorded in human history, causing the death of 75–200 million people, peaking in Europe from 1347 to 1351.

The first European appearance of the Black Death was in Crimea in 1347. From Crimea, it was most likely carried by fleas living on the rats that travelled on Genoese slave ships, spreading through the Mediterranean Basin and reaching Africa, Western Asia and the rest of Europe via Constantinople, Sicily and the Italian Peninsula.

There is evidence that once it came ashore, the Black Death was in large part spread by fleas – which cause pneumonic plague – and the person-to-person contact via aerosols which pneumonic plague enables, thus explaining the very fast inland spread of the epidemic, which was faster than would be expected if the primary vector was rat fleas causing bubonic plague

It depends on what you mean with “Black Death”. The outbreak started in Asia (probably in the Tuva region) around 1330’s, and it arrived in Europe in the mid-1340’s. By the mid-1350’s the first outbreak seemed to have passed pretty much everywhere.

Generally, in each location the outbreak would last 6–9 months, with most victims in the warm months, and minor local outbreaks in the following year or two. So, while overall the outbreak lasted 20 years, at local level the epidemic usually lasted 6–9 months, with less intense repeats in the following years.

On the other hand, the first outbreak was just the first episode of a pandemic that kept the world in its grip until the XVIII century, although with a decreasing intensity. The Marseille plague of 1720 is often quoted as the last major outbreak of the Second Plague Pandemic, which started with the Black Death. So, depending on whether you consider the original outbreak in its whole, the individual local “episodes” of the first outbreak, or the whole pandemic, you may say that the Black Death lasted 20 years, 6–9 months, or 4 centuries.

The conventional wisdom is that the Black Death was caused by the yersinia pestis bacterium, which could cause one of three sets of symptoms:

• Bubonic Plague. This was the most common form of the disease. Symptoms included swollen lymph nodes, purple splotches on the skin, coughing, fever, irritability, and death. These days it’s highly treatable, but in the Middle Ages it had upwards of a 70% fatality rate and, most likely, killed within a week.
• Pneumonic Plague. The chest cold from hell. With pneumonic plague, your lungs would fill with bacteria and mucous causing you to essentially drown. We can also treat this one, but in the Middle Ages it killed roughly 90% of its victims within three or four days.
• Septicaemic Plague. Blood poisoning. If you caught this you were dead within 24 hours with roughly a 100% fatality rate. There is still no known cure.

That said, there are a few theories that the Black Death consisted of more than one disease and it’s possible that pathogens such as anthrax were involved. However, archaeologists have excavated the graves of plague victims and the only pathogen the only pathogen that consistently turns up is yersinia pestis. Other diseases may have been involved, but there’s no evidence that they were particularly widespread.

Some (particularly Scott & Duncan, 2001) argue that the Black Death was caused by a virus. While the recent genetic studies (Haensch et al., 2010) showing the presence of Yersinia Pestis in plague pits has been claimed to prove the Yersinia Pestis theory, there are still problems, such as the speed of spread (too fast for rats), the efficacy of human quarantine (should make less difference) and the prevalence of plague in places where there were few if any rats such as Iceland and Norway (Hufthammer & Walløe, 2013). Furthermore, some plague pits only show small instance of Yersinia Pestis (Tran, Forestier, Drancourt, Raoult, & Aboudharam, 2011). While both these latter studies suggest a flea vector, a recent study has noted that DNA analysis can yield false positives due to the presence of Yersinia Pestis in the soil (Campana, García, Rühli, & Tuross, 2014).

So the problems with the Yersinia Pestis theory, as described in depth by Scott and Duncan (Scott & Duncan, 2001) persist.

The importance of this is that if the black death were viral then it could happen again: one of the zoonotic influenza's (swine flu, bird flu) may wipe out as many people as the black death in the not too distance future, especially because these days we engage in battery farming practices that seem to encourage the formation of a possible new plague virus.

See also the symptoms described at the end of this page on 1918 influenza
Bird Flu - “[A] dead man has no substance unless one has actually seen him dead; a hundred million corpses broadcast through history are no more than a puff of smoke in the imagination.”

Bibliography
Campana, M. G., García, N. R., Rühli, F. J., & Tuross, N. (2014). False positives complicate ancient pathogen identifications using high-throughput shotgun sequencing. BMC Research Notes, 7(1), 111. doi:10.1186/1756-0500-7-111
Haensch, S., Bianucci, R., Signoli, M., Rajerison, M., Schultz, M., Kacki, S., … Bramanti, B. (2010). Distinct Clones of Yersinia pestis Caused the Black Death. PLoS Pathogens, 6(10). doi:10.1371/journal.ppat.1001134
Hufthammer, A. K., & Walløe, L. (2013). Rats cannot have been intermediate hosts for Yersinia pestis during medieval plague epidemics in Northern Europe. Journal of Archaeological Science, 40(4), 1752–1759. doi:10.1016/j.jas.2012.12.007
Scott, S., & Duncan, C., J. (2001). Biology of Plagues: Evidence from Historical Populations. Cambridge University Press.
Tran, T.-N.-N., Forestier, C. L., Drancourt, M., Raoult, D., & Aboudharam, G. (2011). Brief communication: Co-detection of Bartonella quintana and Yersinia pestis in an 11th–15th burial site in Bondy, France. American Journal of Physical Anthropology, 145(3), 489–494. doi:10.1002/ajpa.21510

The Black Death from the 1330s onwards is generally accepted to have been caused by Plague with a capital P - specifically the bacterium Yersinia pestis.

Now, as the bacteria can replicate and cause havoc where they please, a number of disease patterns can be observed, dependent on where they entered the body and spread to. Classically you see 3 patterns commonly described, as they are the most common. However though as with all medical conditions it is never that simple…

Bubonic - Named for causing horrible black sores (buboes) to crop up across the skin. This presentation often comes about from insect bites, infected fleas in particular. The bacteria, having blocked the flea’s digestive tract, are regurgitated into the lymphatic system, through which they spread. After 2–6 days, the illness present with abrupt high fever. The nodes they drain into become focuses of infection, hence the black sores. The spreading infection leads to high fevers, and often progresses to disseminated blood coagulation, causing fingers and toes to blacken. By itself, this condition can be lethal - but of course the bacteria can spread to lungs and the nervous system, or disseminate through the blood. 60% of untreated patients die, often through it progressing to Septicaemia.

Example of groin buboes - a massively swollen set of nodes that have started to fall apart under the skin.

Pneumonic - Either spreading to the lungs by coughs/sneezes (primary), or from infection elsewhere in the body (secondary). Pneumonic plague leads to a severe pneumonia, causing difficulty in breathing and a cough productive of blood. As well as being highly infectious, this presentation of the disease is invariably fatal without treatment - few survive.

Example of a rapidly progressing pneumonia in the R lower and middle lobes of lung, in a plague victim.

Septicaemic Plague

Within the bloodstream, the toxins produced by Plague cause disseminated coagulation and septic shock. The former leads to acral necrosis - gangréné of the périphéries as blood clots cut off supply to these distant body parts. The latter causes systemic inflammation, a drop in blood pressure, and eventually multi organ failure and death.

Example of acral necrosis affecting fingers and nose.

—

As I said though, Yersinia pestis doesn’t just have the run of three systems or presentations…

Pestis Minor

In endemic regions such as Madagascar, a lesser form of the illness has been reported. In these cases, lymph node swelling and a fever flare up, before subsiding in a week without complication.

Meningeal

In some cases, particularly when axillary (armpit) lymph nodes are affected, the plague bacteria can spread to the nervous system. This is characterised by meningitis type symptoms - stiff neck, headache, light aversion. In these cases, antibiotics such as Chloramphenical have to be used to get to the spaces the bacteria start affecting.

Pharyngeal

In cases where substances contaminated by plague are eaten, the plague infection can start in the throat, before spreading to the lymphatic system. Starting with neck nodes, the disease can then progress much like bubonic plague.

Example of a cervical buboe

Gastrointestinal

I have also seen some cases described where plague affects the gut, as a result of ingestion, causing bloody diarrhoea and high fever - though the information is limited.

Endopthalmitis

Cases are described of plague affecting the eye, leading to visual disturbance and blindness.

As you can see, there are many more uncommon presentations of plague. Unfortunately, as millions were affected by the Black Death of the 14th century, many people would have been affected by these different disease presentations. One can only imagine the horror.

There are three recognised pandemics caused by the plague bacillus, Yersinia pastis. The first is known to western historians as the Plague of Justinian, because it devastated Europe, western Asia and North Africa on its first appearance during the reign of the Roman Emperor Justinian in the 6th century. It recurred several times before apparently dying out in the early 8th century. Not much is known about its origins.

The second pandemic started with the outbreak known in the west as the Black Death. It seems to have started in western China or Mongolia in the early 14th century before spreading throughout the old world, although there are other hypotheses. It is suggested that it may have been brought west by Mongolian military supply lines. After the initial devastation it became endemic and localised outbreaks occurred in various places until the early 19th century. The last big outbreak was in Baghdad in the 1820s. The Wikipedia article on the Second Plague Pandemic includes a table of the most important outbreaks.

The third pandemic started towards the end of the 19th century and was largely contained to China and India, although outbreaks occurred in the western United States and it is endemic there in an animal reservoir, and also in Madagascar. These days plague can be largely controlled by antibiotics.

Archaeological genetic evidence suggests that Y. pestis has been around a lot longer than this, though.