The Black Death is basically the term given to the outbreak of the bubonic plague in Europe and in Mediterranean in the early 14th century, somewhere around 1347 through 1351. Actually it was the first of the many cycles of epidemic plagues that struck entire Europe until the 17th century and sparingly followed in the next centuries afterward. The occurrence of the last known plague was sometime around 1722 in Marseilles. It was also considered as the last known major outbreak. All the plagues that followed after that were minor plagues that quickly disappeared in a relatively short span of time. In fact these plagues' predecessors started way back during the ancient plagues that took place sometime the 6th and 8th century A.D. Following that, were more modern versions of the epidemic plagues and were also less deadly. They have began starting from the 19th century and somehow followed through until the early 20th century. The chronic epidemic that struck Europe wasn't called "The Black Death" at first until much later. Contemporaries often call the centuries' long epidemic phenomenon as "The Great Mortality" or "The Pestilence".
The Plague were series of bacterial infection which could take more than just one state or form in the host. High fever and certain amounts of swellings in the armpit or in the groin are just some of the symptoms commonly manifested from a victim of the bubonic plague. Back then, modern antibiotics that can deal with the infections were still not invented and 60 percent of the infected populace will inevitably die within the first 5 days of the infection. Pneumonic and Septicemic plagues were also amongst the other forms of the plague and are proven to be quite as deadly as well. It was though that the disease was carried through critter hosts such as rodents, prairie dogs, and marmots etc. The disease is then transmuted to human hosts through fleas that just fed on infected rodent blood that would then attach themselves to human host. Other means of disease communication is through rodent feces and urine which should be naturally infected as well.
Until now, scientists and historians are still uncertain of the exact origins of The Black Death. Medieval chroniclers and early European historians theorized that the disease originated in China because the land's association with magical orientations. According to Chroniclers, the plague came with earthquakes, vermin plagues, and fire falling from the sky. However, this was associated with folklore and myths and the hypothetical interpretations with life outside of Europe. According to more recent researches, the disease has most likely migrated from the Middle-East to southern Russia and the areas somewhere in between the Black Sea and Caspian Sea. The plague then spread out through west along the trade routes. Epidemics were already then proliferating among the Tartars in the Southern parts of Russia around 1346. Merchants have then probably carried the disease along the access trade routes and thus the plague has reached the Italians residing in the towns near the Black Sea. In the same manner, merchants originating from that place have relocated the disease to Alexandria, Egypt sometime 1347; moving to Libya and Damascus in 1348 and then Upper Egypt in the following year. Genoese and Venetian sailors are believed to have extended the plague to Europe.
From then the plague quickly accessed places in Europe via trade routes. Beginning its arrival on 1348 in Pisa, the disease traveled across to Florence then Rome and Bologna; then starting from Venice, it then again moved to Germany and Austria, then to Genoa and eventually to Spain. By June of 1348 it has reached France and finally the contagion has reached England in beginning of summer 1349.
Causes of the Plague
The contemporary doctors and theologians have all agreed that the plague were both religious and medical in nature. One of their beliefs was the disease was brought down as the wrath of God in order to punish the sinfulness of humans. Another belief was it was caused by the lack of balance in the body fluids. The accounts of earthquakes, floods and tongues of fire falling from the sky preceding the plague, were indications that the illness was a call to repentance according to early Christians. As a reply to that calling, some of those Christians have formed groups they would later come to name as Flagellants and they then began to ritually lash and beat themselves as penance for their sins and as well for others. Their existence sometime around the 10th century did not mitigate the outbreak of the plague. Instead the contagion exponentially increased throughout Europe.
Contemporary medieval physicians derived their medical ideas from the early Greeks and Romans whom have believed that the cause of the plague were the disruption of the body system's balance, particularly the fluids within the body. Imbalances can be caused by sudden emotional outbursts or inequitable distribution of diet and other external factors that could potentially invade and disrupt the natural balance in the body. Writers on the other hand theorized that the plague was celestially associated. As stars and planets have beset influence to the earth thus causing earthquakes which would then result to the emission of noxious gasses out from the earth's surface. They believed that these gases primarily caused the disease to spawn. Physicians then immediately promulgated protocols to avoid anything that would potentially disrupt the body's delicate natural balance. The government as well regulated the trade and production of dangerous odors or any matter that is potentially corrupted.
There occurrences of epidemics somewhere around the late 14th and 15th centuries, however, they were less virulent as its predecessors. The contemporaries have begun to see through the patterns of the plague and sense what they could possible do to counteract and mitigate the gravity of the plague. They discovered after some time observing, that the disease is most likely to spawn in the summer or early fall. Furthermore, they have also noticed that the plague is highly concentrated in the most urban poorest areas. Mostly in areas where there is a highly congested population with tightly closed neighborhood is where the plague's concentration's at peak. An Italian, Girolamo Fracastoro, explained that it was the poor who were spreading out the disease. His assumptions have lead to the avoidance of people from any poor or sick person encounter as it was the only best defense against contagion. Those who were capable of relocating transferred themselves to distant areas far from the poor neighborhood or villages, thus, far from the contagion.
There were also quarantines implemented as a counteractive measure against the plague, however, with the multitude of the infected people and the widespread contagion it was almost impossible to quarantine and contain the affected population.
At the onset of the late 17th century, governments have begun implement medical boundaries or cordon sanitaire between Europe and the eastern parts where the disease has been said to have come from. Ships coming from those areas were forced to cease to implement specialized quarantine procedures before anyone or anything is unloaded from the ship. Quarantines were so strictly implemented that anyone who would try to avoid by running away from implementing personnel were shot.
Here's Pest Mice and Plague (Part II).