The second plague pandemic is a major series of epidemics of the plague that started with the Black Death, which reached mainland Europe in 1348 and killed up to a third of the population in the next four years. Although it died out in most places, it became epizootic and recurred regularly until the nineteenth century. A series of major plagues occurred in the late 17th century and it recurred in some places until the 19th. After this a new strain of the bacterium appeared as the third pandemic.
Plague is caused by the bacterium Yersinia pestis which exists in the fleas of several species in the wild and particularly rats in human society. In an outbreak it may kill all its immediate hosts and thus die out, but remain active in other hosts which it does not kill and thereby cause a new outbreak years or decades later. It has several means of transmission and infection, including rats carried on board ships or vehicles, fleas hidden in grain, and in its more virulent forms is transmitted by blood and sputum directly between humans.
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.
The Second pandemic originated in or near China and spread by way of the Silk Road or by ship. It may have reduced world population from an estimated 450 million down to 350–375 million by the year 1400.
The plague returned at intervals with varying virulence and mortality until the early 19th century. In England, for example, the plague returned in 1360–63 killing 20% of Londoners and in 1369 killing 10–15%. In the 17th-century outbreaks were a series of "great plagues": the Great Plague of Seville (1647–52); the Great Plague of London (1665–66); and the Great Plague of Vienna (1679). In its virulent form, after the Great Plague of Marseille in 1720–22, the Great Plague of 1738 (which hit Eastern Europe), and the Russian plague of 1770–1772, it seems to have gradually disappeared from Europe though lingering in Egypt and the Middle East. By the early 19th century, the threat of plague had diminished, but it was quickly replaced by a new disease. The Asiatic cholera was the first of several cholera pandemics to sweep through Asia and Europe during the 19th and 20th centuries.
The Third Pandemic hit China in the 1890s and devastated India, but was largely contained in the east, though becoming endemic in the Western United States. It still causes sporadic outbreaks.
Arab historians Ibn Al-Wardni and Almaqrizi believed the Black Death originated in Mongolia, and Chinese records show a huge outbreak in Mongolia in the early 1330s. Europe was initially protected by a hiatus in the Silk Road, but a 1347 Mongolian siege at Caffa—the last Italian outpost on the Crimean Peninsula—spread it to the defenders, who carried it back with them that winter. It arrived at Genoa and Venice in January 1348, while simultaneously spreading through Asia Minor and into Egypt. The bubonic form was described graphically in Florence in The Decameron and Guy de Chauliac also described the pneumonic form at Avignon. It rapidly spread to France and Spain, by 1349 was in England, in 1350 was afflicting eastern Europe and it reached the centre of Russia by 1351. In most parts it blew itself out within about three years, though only temporarily.
The 14th-century eruption of the Black Death had a drastic effect on Europe's population, irrevocably changing the social structure, and resulted in widespread persecution of minorities such as Jews, foreigners, beggars, and lepers (see Persecutions). The uncertainty of daily survival has been seen as creating a general mood of morbidity, influencing people to "live for the moment," as illustrated by Giovanni Boccaccio in The Decameron (1353).
There were large epidemics in China in 1331 and 1351-54 in Hopei, Shansi and other provinces which are considered to have killed between 50% and 90% of the local populations, running into tens of millions. However, there is no proof currently that these were caused by plague though there are indications for the second set of epidemics.
The plague repeatedly returned to haunt Europe and the Mediterranean throughout the 14th to 17th centuries. According to Biraben, plague was present somewhere in Europe in every year between 1346 and 1671. Subsequent outbreaks, though severe, marked the retreat from most of Europe (18th century) and northern Africa (19th century). According to Geoffrey Parker, "France alone lost almost a million people to plague in the epidemic of 1628–31."
In 1466, perhaps 40,000 people died of plague in Paris. During the 16th and 17th centuries, plague visited Paris for almost one year out of three. The Black Death ravaged Europe for three years before it continued on into Russia, where the disease hit somewhere once every five or six years from 1350 to 1490. Plague epidemics ravaged London in 1563, 1593, 1603, 1625, 1636, and 1665, reducing its population by 10 to 30% during those years. Over 10% of Amsterdam's population died in 1623–1625, and again in 1635–1636, 1655, and 1664. There were 22 outbreaks of plague in Venice between 1361 and 1528. The plague of 1576–1577 killed 50,000 in Venice, almost a third of the population. Late outbreaks in central Europe included the Italian Plague of 1629–1631, which is associated with troop movements during the Thirty Years' War, and the Great Plague of Vienna in 1679. Over 60% of Norway's population died from 1348 to 1350. The last plague outbreak ravaged Oslo in 1654.
In the first half of the 17th century, a plague claimed some 1.7 million victims in Italy, or about 14% of the population. In 1656, the plague killed about half of Naples' 300,000 inhabitants. More than 1.25 million deaths resulted from the extreme incidence of plague in 17th-century Spain. The plague of 1649 probably reduced the population of Seville by half. In 1709–1713, a plague epidemic that followed the Great Northern War (1700–1721, Sweden v. Russia and allies) killed about 100,000 in Sweden, and 300,000 in Prussia. The plague killed two-thirds of the inhabitants of Helsinki, and claimed a third of Stockholm's population. Western Europe's last major epidemic occurred in 1720 in Marseilles, in Central Europe the last major outbreaks happened during the plague during the Great Northern War, and in Eastern Europe during the Russian plague of 1770-1772 The plague ravaged much of the Islamic world. Plague was present in at least one location in the Islamic world virtually every year between 1500 and 1850. Plague repeatedly struck the cities of North Africa. Algiers lost 30,000–50,000 to it in 1620–21, and again in 1654–57, 1665, 1691, and 1740–42. Plague remained a major event in Ottoman society until the second quarter of the 19th century. Between 1701 and 1750, 37 larger and smaller epidemics were recorded in Constantinople, and 31 between 1751 and 1800. Baghdad has suffered severely from visitations of the plague, and sometimes two-thirds of its population has been wiped out.
The second pandemic never became endemic in Europe. Most epidemics arrived with shipping from the near east and died out after a few years. But the pandemic died out progressively across Europe. One documented case was in 17th century London, where the first proper demographer, John Graunt, failed by just 5 years to see the last recorded death from plague, which happened in 1679, 14 years after the Great Plague of London. The reasons it died out totally are not well understood. It is tempting to think that the Great Fire of London the next year destroyed the hiding places of the rats in the roofs. Certainly there isn't a single plague death recorded "within the walls" after 1666. However the city by this time had spread well beyond the walls which contained most of the fire and most of plague cases happened beyond the limits of the fire. Probably more significant was the fact that all buildings after the fire were constructed of brick rather than wood and other flammable materials.
This pattern was broadly followed after major epidemics in northern Italy (1631), south and east Spain (1652), southern Italy and Genoa (1657), Paris (1668).
Appleby considers six possible explanations:
- People developed immunity.
- Improvements in nutrition made people more resistant.
- Improvements in housing, urban sanitation and personal cleanliness reduced the number of rats and rat fleas.
- Change in dominant rat species. (The brown rat didn't arrive in London until 1727)
- Quarantine methods improved in the 17th century.
- Some rats developed immunity so fleas never left them in droves to humans, non-resistant rats were eliminated and this broke the cycle.
Probably most of these have some weight, but the answer is unclear.
The disappearance happened rather later in the Nordic and eastern European countries but there was a similar halt after major epidemics. In the middle east and north Africa, epidemics continued to occur.