There have been three major outbreaks of plague. The Plague of Justinian in the 6th and 7th centuries is the first known attack on record, and marks the first firmly recorded pattern of bubonic plague. From historical descriptions, as much as 40% of the population of Constantinople died from the plague. Modern estimates suggest half of Europe’s population died as a result of the plague before it disappeared in the 700s. After 750, major epidemic diseases did not appear again in Europe until the Black Death of the 14th century.

Catastrophes struck much of Europe during the 13th to 16th centuries. From Mongol inflicted suffering in China, to creating conditions which enabled the Black Death to arise and devastate the Chinese population and then spread across Europe and the Middle East, due to Mongol armies and trading routes carrying the disease. During the 13th century Mongol conquest, farming and previous trading practices were disrupted with the result of widespread famine in China. The population dropped from approximately 120 to 60 million. On top of all this misery came the 14th century plague – the Black Death. It is estimated to have reduced the remaining population of China by a third.

During the Medieval Warm Period (the period prior to 1300), the population of Europe exploded compared to prior eras, reaching levels that were not matched again in some places until the nineteenth century – indeed parts of rural France today are less populous than at the beginning of the fourteenth century. However, the yield ratios of wheat, the number of seeds one could eat per seed planted, had been dropping since 1280, and food prices had been climbing. After favourable harvests, the ratio could be as high as 7:1, but after unfavourable harvests it was as low as 2:1 – that is, for every seed planted, two seeds were harvested; one for next year’s seed, and one for food. By comparison, modern farming has ratios of 30:1 or more.

From 1315 to 1317 a catastrophic famine, known as the Great Famine, struck much of North-West Europe. It began with bad weather in spring 1315. Crop failures lasted through 1316 until the summer harvest in 1317, and Europe did not fully recover until 1322. The period was marked by extreme levels of crime, disease, mass death and even cannibalism and infanticide. The crisis had consequences for the Church, state, European society, and for future calamities to follow in the fourteenth century.

The European economy entered a vicious circle in which hunger and chronic, low-level debilitating disease reduced the productivity of labourers, and so the grain output was reduced, causing grain prices to increase. This situation was worsened when landowners and monarchs like Edward III of England (r. 1327–1377) and Philip VI of France (r. 1328–1350), out of a fear that their comparatively high standard of living would decline, raised the fines and rents of their tenants. Standards of living then fell drastically, diets grew more limited, and Europeans as a whole experienced more health problems.

Heavy rains in autumn 1314 began several years of cold and wet winters. The already weak harvests of the north suffered and the seven-year famine ensued. The Great Famine was the worst in European history, reducing the population by at least ten percent. Records recreated from dendrochronological studies show a hiatus in building construction during the period, as well as a deterioration in climate.

This was the economic and social situation in which the predictor of the coming disaster, a typhoid (Infected Water) epidemic, emerged. Many thousands died in populated urban centres, most significantly Ypres. In 1318 a pestilence of unknown origin, sometimes identified as anthrax, targeted the animals of Europe; notably sheep and cattle, further reducing the food supply and income of the peasantry.

Then came the Black Death

The continual wars, famine, and weather contributed to the severity of the Black Death, whose devastating impact massively reduced the populations which had previously flourished.

It is now thought there were two different plagues that formed the Black Death – Bubonic and Pneumonic. Bubonic is spread by fleas carrying plague bacillus, and Pneumonic is spread through coughing and sneezing the germs.

The Yersinia pestis bacterium, which exists in the fleas of several species in the wild and particularly rats in human society, may kill all its immediate hosts and thus die out. However, it can remain active in other hosts which it does not kill and thereby cause a new outbreak years or decades later. Of course, rats are carried on board ships or vehicles, fleas can be hidden in grain. An infected human can transmit the disease by blood and sputum to other humans.

Bubonic plague infection causes tiny blood vessels in the feet and toes to clog up and cut off circulation. Without blood, the flesh dies and turns black (called “gangrene”). This is why in the Middle Ages bubonic plague was called “the Black Death.”

The Black Death, caused by Yersinia pestis, is enzootic (commonly present) in populations of ground rodents in Central Asia. Morelli et al. (2010) reported the origin of the plague bacillus to be in China. An older theory places the first cases in the steppes of Central Asia, and others, such as the historian Michael W. Dols, argue that the historical evidence concerning epidemics in the Mediterranean and specifically the Plague of Justinian point to a probability that the Black Death originated in Central Asia (not Africa – Africa (http://www.medicalnewstoday.com/articles/206309.php) where it then became entrenched among the rodent population.

Nevertheless, from Central Asia it was carried east and west along the Silk Road, by Mongol armies and traders making use of the opportunities of free passage within the Mongol Empire offered by the Pax Mongolica. During the early 1300s they were still expanding their empire.

1300 Mongol invasion of Myanmar

1300 Mongol invasion of Syria

1303 Invasion of Syria

1307 Mongol invasion of Gilan

1312 Mongol invasion of Syria

1324, 1337 Mongol raids against Thrace

1337, 1340 Mongol raids against Poland

The Mongols had divided into Hordes: The Golden Horde, the Blue Horde and the White Horde. Each Horde was led by a descendant of Genghis Khan. One of notorious fame was Jani Beg (who died 1357) also called Djanibek Khan and he was a khan of the Golden Horde from 1342 to 1357, succeeding his father Öz Beg Khan.

After putting two of his brothers to death, Jani Beg crowned himself in Saray-Jük. He is known to have actively interfered in the affairs of Russian principalities and of Lithuania. The Grand Princes of Moscow, Simeon Gordiy, and Ivan II, were under constant political and military pressure from Jani Beg.

Jani Beg commanded a massive Crimean Tatar force that attacked the Crimean port city of Kaffa in 1343. The siege was lifted by an Italian relief force in February. In 1345 Jani Beg again besieged Kaffa; however, his assault was again unsuccessful due to an outbreak of the Black Plague among his troops. It is thought that Jani Beg’s army catapulted infected corpses into Kaffa in an attempt to use the Black Death to weaken the defenders. Infected Genoese sailors subsequently sailed from Kaffa to Sicily, introducing the Black Death into Europe.

But Russia was very cold and the bacterium, fleas and rats would not survive. Once transferred to warmer conditions, the bacteria thrived, and from the start of the plague, only subsided when cold conditions occurred, then reappeared once it was warmer. Thus only pockets of infection spread in the required conditions.

In October 1347, a fleet of Genoese trading ships fleeing Caffa reached the port of Messina in Sicily. By the time the fleet reached Messina, all the crew members were either infected or dead. It is presumed that the ships also carried infected rats and/or fleas. Some ships were found grounded on shorelines, with no one aboard remaining alive.

Looting of these lost ships also helped spread the disease. From there, the plague spread to Genoa and Venice by the turn of 1347–1348.

At Siena, in central Italy’s Tuscany region, Agnolo di Tura wrote:

“They died by the hundreds, both day and night, and all were thrown in … ditches and covered with earth. And as soon as those ditches were filled, more were dug. And I, Agnolo di Tura … buried my five children with my own hands … And so many died that all believed it was the end of the world.”

Italy, returning in the 16th to 17th centuries:

The plague of 1575–77 claimed some 50,000 victims in Venice. 

Italian Plague of 1629–1631, which is associated with troop movements during the Thirty Years’ War.

In 1656 the plague killed about half of Naples’ 300,000 inhabitants. 

From Italy the disease spread northwest across Europe:

France reoccurred The Great Plague of Marseille was the last of the significant European outbreaks of bubonic plague. Arriving in Marseille, France in 1720, the disease killed 100,000 people in the city and the surrounding provinces.

Spain: the Crown of Aragon, the Crown of Castille, The Black Death in Aragon, 1348–1351.

Comparative neglect of the effects of the Black Death in Aragon makes a collection of documents published in 1956 by Dr López de Meneses particularly valuable. Over half the documents, mostly dating between 1348 and 1351, describe the disruption and disorder which occurred in the administrative and economic spheres, and it is on these that this study will focus. King Pedro IV showed flexibility and pragmatism in his treatment of the crisis, but normal administrative processes were only slowly restored, and people took full advantage of the shortage of officials and the loss and discontinuity of legal records. Economically, the royal treasury suffered an almost immediate drop in income. The king could not grant financial aid to his subjects, but lessened taxes and tributes, and frequently interceded on behalf of the Jews. The king also issued useless price and wage controls.The documents shed little light on the problem of mortality dates, but they vividly illustrate the confusion, fraud, and lawlessness which occurred in the aftermath of the plague. There is no indication that the epidemic caused changes in the fundamental character of any Aragonese institution, or that the king’s activities were paralyzed by the crisis. Though grave, the damages of this first plague were not irreparable. See http://www.tandfonline.com/doi/abs/10.1016/0304-4181(81)90014-2

The plague returned to Spain 1647 – 52, known as the Great Plague of Seville.

Portugal 1348-49, like the rest of Europe, Portugal was devastated by the Black Death which probably killed one third of the population.

England by June 1348 – and it recurred over centuries 

In England, in the absence of census figures, historians propose a range of pre-incident population figures from as high as 7 million to as low as 4 million in 1300, and a post-incident population figure as low as 2 million. By the end of 1350 the Black Death had subsided, but it never really died out in England over the next few hundred years: there were further outbreaks in 1361–62, 1369, 1379–83, 1389–93, and throughout the first half of the 15th century. The plague often killed 10% of a community in less than a year—in the worst epidemics, such as at Norwich in 1579 and Newcastle in 1636, as many as 30 or 40%. The most general outbreaks in Tudor and Stuart England, all coinciding with years of plague in Germany and the Low Countries, seem to have begun in 1498, 1535, 1543, 1563, 1589, 1603, 1625, and 1636.

The Great Plague of London in 1665–1666 is generally recognized as one of the last major outbreaks.

From England it spread east through:

Germany (and recurring In 1634, an outbreak of plague killed 15,000 Munich residents). The plague reoccurred in Austria in the Great Plague of Vienna in 1679. 

Scandinavia from 1348 to 1350. Norway in 1349 when a ship landed at Askøy, then proceeded to spread to Bjørgvin (modern Bergen). Oslo was last ravaged in 1654. Amsterdam was ravaged in 1663–1664, with a mortality given as 50,000.

The Black Death hit north-western Russia in 1351. It recurred in Moscow causing the deaths of 200,000, 1654 to 1656. 

Parts of Europe spared in the first spread of the disease:

Poland, isolated parts of Belgium and the Netherlands, Milan and the modern-day France-Spain border.

As it spread to western Europe, the disease arrived in:

Southern Russia

By autumn 1347, the plague reached Alexandria in Egypt, probably through the port’s trade with Constantinople, and ports on the Black Sea. 

During 1348, the disease traveled eastward to Gaza, and north along the eastern coast to cities in Lebanon, Syria, and Palestine, including Ashkelon, Acre, Jerusalem, Sidon, Damascus, Homs, and Aleppo. 

In 1348–49, the disease reached Antioch. The city’s residents fled to the north, most of them dying during the journey, but the infection had been spread to the people of Asia Minor.

Mecca became infected in 1349. During the same year, records show the city of Mawsil (Mosul) suffered a massive epidemic, and the city of Baghdad experienced a second round of the disease. 

In 1351, Yemen experienced an outbreak of the plague. This coincided with the return of King Mujahid of Yemen from imprisonment in Cairo. His party may have brought the disease with them from Egypt.

2017

Most recently, an outbreak of the plague started in Madagascar at the end of August, and has infected 138 people, killing 47. The body count is feared to grow as the disease has now reached Antananarivo, Madagascar’s capital city.  The disease is airborne and could reach the East African coast. See http://www.iflscience.com/health-and-medicine/bubonic-plague-outbreak-spreads-madagascar/

2018
Computer modelling carried out by a research team from the universities of Oslo and Ferrara suggests the first outbreak may not have been down to the rats, but instead can be “largely ascribed to human fleas and body lice”.