THE BUBONIC PLAGUE OF 1348.

The disastrous mortal disease known as the Bubonic Plague came out of the East and spread, unleashing a rampage of death across Europe in the years 1346-53. The Plague reached the shores of Italy in the spring of 1348. Three years later, anywhere between 25% to 50% of Europe's population had fallen victim to the pestilence.
In Florence, the poet Petrarch, who was lost to the Plague with his beloved wife and children, wrote: "All the citizens did little except to carry dead bodies to be buried. At every church they dug deep pits down the water-table. In the morning when a large number of bodies were found in the pit, people took some earth and shoveled it down .. ."
Another chronicler, Agnolo di Tura relates from his Tuscan home town that "... in many places in Siena great pits were dug and piled deep with multitude of dead and there were bodies that were sparsely covered with earth that the dogs dragged them forth and devoured many bodies through the city."
The tragedy was extraordinary in the city of Florence. In the course of just a few months, 60% of the population died from the plague, and the same proportion in Siena.
The epidemic was caused by the bacterium "Yersina pestis" that circulates among wild rodents where they live in great numbers and density. Plague among humans arises when the rodents, normally black rats, in human habitation, become infected. The black rat, also called the "House Rat" and the "Ship Rat," likes to live close to people, the very quality that makes it dangerous. In contrast, the brown or grey rat prefers to keep its distance living in sewers and cellars.
Normally, it takes 10 to 14 days before the plague has killed off most of a contaminated rat colony. After 3 days of fasting, hungry fleas turn on humans. From the bite site, the contagion drains to a lymph node that consequently swells 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.
In order to become an epidemic the disease must be spread to other rat colonies in the locality and transmitted to inhabitants in the same way. It took some time for people to recognize that a terrible epidemic was breaking out among them.
Importantly, plague was spread considerable distances by rat fleas on ships. Infected ship rats would die, but their fleas would often survive and find new rat hosts wherever they landed.
The Plague presented itself in three interrelated forms. The most common bubonic variant is that of infected fleas attached themselves to black rats and then spread to humans. Although some survived the painful ordeal, the manifestation of these lesions usually signaled the victim had a life expectancy of up to a week. A second variation presented was -the pneumonic plague attacked the respiratory system and was spread by merely breathing the exhaled air of a victim. It was much more virulent than its bubonic cousin -life expectancy was measured in one or two days. Finally, the septicemic version of the disease attacked the blood system.
The violence of this plague was such that the sick communicated it to the healthy who came near them, just as fire catches anything dry or oily near it. Such fear took possession of the living that almost all of them avoided the sick and everything belonging to them. They formed small communities, living entirely separate from everybody else. They shut themselves up in houses where there were no sick, allowing no news or discussion of death and sickness.
In this suffering and misery, the authority of human and divine laws almost disappeared, for, like other men, the ministers and executors of the laws were all dead or sick, so that no duties were carried out.
Many individuals adopted a course of life in the middle. They did not restrict their victuals, nor allowed themselves to be drunken, but satisfied their appetites moderately. They did not shut themselves up, but went about, carrying flowers or scented herbs or perfumes in their hands, for the whole air was infected with the smell of dead bodies.
Others abandoned their own cities, their own houses, their relatives and their properties, and went abroad, as if God's wrath in punishing men's wickedness with this plague would not follow them but strike only those who remained within the walls of the city. Such terror struck into their hearts by this calamity, that brother abandoned brother, sister her brother, and very often the wife her husband. Fathers and mothers refused to see and tend their children, as if they had not being theirs.
A multitude of sick men and women were left without care. Most of them remained in their houses. Others ended their lives in the streets both at night and during the day. Dead bodies filled every corner of the walled cities. The cemeteries were full forcing to dig huge trenches,where they buried bodies by hundreds.
The Plague had an enormous impact on European society and greatly affected the dynamics of change and development from the medieval to Early Modern period.