And I Agnolo di Tura, called the Fat buried my five children with my own hands. And there were also those who were so sparsely covered with earth that the dogs dragged them forth and devoured many bodies throughout the city.”
The likely consequence of having large numbers of decaying bodies was both to accelerate the transmission of the plague through the conventional vectors of rats and fleas, and also to introduce a whole series of other diseases associated with putrefaction so that there may have been significant numbers who died of diseases other than the plague.
Of the various chronicle accounts of the plague the best by far is that of secular author Giovanni Boccaccio who gave a long and detailed account of the impact of the plague on his native city of Florence.
‘I say, then, that the years of the era of the fruitful Incarnation of the Son of God had attained to the number of one thousand three hundred and forty eight when into the notable city of Florence, fair over every other in Italy, there came the death dealing pestilence, which, through the operation of the heavenly bodies or our own iniquitous dealings, being sent down upon mankind for our correction by the just wrath of God, had some years before appeared in the parts of the East, and, after having bereft these latter of an innumerable number of inhabitants, extending without cease from one place to another, had now spread towards the West. And thereagainst no wisdom availing nor human foresight (whereby the city was purged of many impurities by officers deputed to that end and it was forbidden unto any sick person to enter therein and many were the counsels given for the preservation of health) nor yet humble supplications, not once, but many times both in ordered processions and in other ways made unto God by devout persons - about the coming in of Spring of the aforesaid year, it began in a horrible and miraculous way to show forth its dolorous effects. Yet not as it had done in the East, where if any bled at the nose, it was a manifest sign of inevitable death; nay, but in men and women alike there appeared at the beginning of the malady, certain swellings, either on the groin or under the armpits, whereof some waxed of the bigness of a common apple, other like unto an egg, some more and some less, and these the vulgar named plague boils. From these two parts the aforesaid death-bearing plague boils proceeded, in brief space, to appear and come indifferently in every part of the body; where from, after awhile, the fashion of the contagion began to change into black or livid blotches, which showed themselves in many first on the arms and about the thighs and after spread to every other part of the person, in some large and sparse, and in others small and thick sown; and like as the plague boils had been first (and yet were) a very certain token of coming death, even so were these for everyone to whom they came. To the cure of these maladies neither counsel of physician nor virtue of any medicine appeared to avail or profit aught; on the contrary - whether it was that the nature of the infection suffered it not or that the ignorance of the physicians .. Availed not to know whence it arose and consequently took not due measures thereagainst- not only did few recover thereof, but well nigh all died within the third day from the appearance of the aforesaid signs, this one sooner and that later, and for the most part without fever or other accident. And this pestilence was the more virulent because by communication with those who were sick thereof, it got hold upon the ground, as fire upon things dry or greasy, when they were brought very near hereunto. Nay, the harm was yet greater; for that not only did conversation and consorting with the sick give infection to the sound or cause of common death, but the mere touching of the clothes or whatsoever other things had been touched by the sick appeared to communicate the malady to the toucher.......From these things, and many others like unto them or yet stranger divers fears and conceits were begotten in those who abode alive, which well nigh all tended to a very barbarous conclusion, namely to shun and flee from the sick and all that pertained to them, and thus doing, each thought to secure immunity for himself.”
Boccaccio’s account is consistent with other Chroniclers so far as the gross symptoms are concerned, though others note cases where death could strike more quickly and without the external symptoms of the plague boils or buboes. Most also agree that the plagues was in some way associated with celestial events. Knighton talks about it following the course of the sun. The French chronicler Jean de Venette talks about a comet exploding over Paris and attributes the plague to its presence. The problem was definitively resolved in October 1348 by astronomers at the University of Paris who concluded that the plague arose from a conjunction of Saturn, Jupiter and Mars in the 40th degree of Aquarius. Others saw the plague as a kind of cloud or miasma which drifted across Europe infecting as it went. Most agreed that whatever the prime cause the plague had come from the East, either from China or India.
Contemporaries had no real idea what the plague was or how it was transmitted. Their medical knowledge was insufficient to provide any sort of remedy and they had no form of scientific explanation for its symptoms. The symptoms described by the Chroniclers, especially the swellings in the armpits are consistent with what we now know to be the bubonic plague which is an infective disease cause by the bacillus pasteurella pestis. Pasteurella pestis is communicated by a complicated chain of vectors including the medieval black rat, rattus rattus, and the rat’s symbiotic flea Xenopsylla Cheopsis. The infection is transmitted to humans either by a bite from an infected rat or an infected flea. Medieval living conditions were peculiarly conducive to such forms of infection. Rats were always close companions of humans, even closer than they are today, and the simple wattle and daub thatched houses of ordinary people in both town and country provided an ideal habitat for all kinds of parasites. Houses did not have ceilings so rat fleas could easily drop from the thatch onto the humans (and animals) beneath. Bubonic plague is now well understood. It still occurs from time to time in America and India where it is endemic in regions where there are substantial colonies of burrowing rodents. It occurred with particular virulence in Manchuria in 1911 and 1921 when it was extensively studied by Western epidemiologists. We now know that the plague can exist in three forms, bubonic, so called because of the buboes or swellings, which are the obvious visible symptom, communicated by flea of bites and attacking the human lymphatic system. Simple Bubonic plague kills within five days. Pneumonic plague occurs where a victim develops pneumonia as a consequence of first getting bubonic plague. The bubonic infection is then communicated by exhalation and affects the bronchial system of the next host directly. The Pneumonic variant kills within 2 - 3 days or less. The third variant, septicaemic plague is extremely rare and occurs where the bloodstream is directly affected rasing the concentration of bacilli in the bloodstream to a level at which it can be transmitted directly by the human flea Pulex Irritans without passing through the intermediary host of the rat. This can kill within hours and explains contemporary accounts of people who went to bed apparently well and when they awoke in the morning they were, like the biblical Assyrians (also victims of a god sent plague) all dead men.
The bubonic form of the plague is the one most widely described by chroniclers and contrary to popular belief can be survived, especially if the buboes burst or are lanced, though this was not understood at the time. Both the pneumonic and the septicaemic varieties were 100% lethal and could kill within a very short space of time. The Pneumonic variety however could be transmitted only by close human contact, in the same way as influenza today, but it accounts for the high mortality amongst monks, priests and other tending to the dying who put their faces close to the patient. Since those infected in this way were unlikely to get far in the period between infection and death the pneumonic plague remained localised within families and communities, for example monasteries where it could spread like wildfire. Henry of Knighton, a regular Canon in the Abbey at Leicester and opponent of the Franciscan Order reported the death of the entire population of 150 Friars in a Franciscan monastery in Marseilles adding as a malicious afterthought, a good thing too. The bubonic version also kills its hosts, but more slowly, especially in the case of the flea which can survive dormant for weeks, even months, in the goods of a travelling merchant. The bacillus pasteurella pestis will, however, die off when it has itself killed off all accessible and susceptible hosts, whether human, rat or flea. In order to sustain itself the bacillus must find a host which is not affected by it or which reproduces faster than the bacillus can kill the host. The question which interests historians, then, is how did the bubonic plague get into Europe and where did it come from.
The question can be approached on two levels. Firstly , contemporaries, as I have said, believed that it came from India or China as a consequence of miraculous astrological events, and were aware that a savage plague was raging in the Far East and had reached the Crimea by 1346. The local Tartars blamed the enclave of Christian merchants, since anything bad is always cause by foreigners or the English. The Christians fled to their trading base in the town Caffa which was besieged by a Tartar army. The Tartars were then struck down by the plague to the extent that they could not continue the siege but as a Parthian shot they catapulted the bodies of the plague victims into the town, and then withdrew. The Christians in Caffa fled in their galleys back to their home ports in the Mediterranean, the first arriving at Messina in Sicily in October 1347 with half the crew dead and the other half fingering their buboes, and exuding foul smelling materials from every bodily orifice. A Flemish chronicler described the arrival of plague bearing galley in Genoa in January 1348:
‘horribly infected and laden with a variety of spices and other valuable goods. When the inhabitants of Genoa learned this, and saw how suddenly and irremediably they infected other people, they were driven forth from that port by burning arrows and divers engines of war; for no one dared to touch them; nor was any able to trade with them, for if he did he would be sure to die forthwith. Thus they were scattered from port to port.’ Clearly the rulers of Genoa were sufficiently smart to realise the dangers of contagion, even if they did not realise what they were up against. It was, however, too late. The plague spread up the rivers and trade routes from the Mediterranean into Northern Europe reaching England by June 1348. That accounts for the historical evidence of the introduction of the plague into Europe. Its progress during the next twelve months can by fairly accurately charted from contemporary accounts.
The second question concerns modern understanding of the aetiology of the plague. Where did it come from and how was it actually spread ? Contemporary accounts of China as the source of the plague are hard to sustain because the plague broke out in China shortly after it had reached Europe and cannot therefore have initiated the movement to the West. The most plausible modern explanation of the origins of the plague is given by William H. McNeill, in Plagues and Peoples. McNeill argues that the bacillus pasteurella pestis would not survive long in human populations because once exposed to it the survivors either die or develop an immunity. It was lethally dangerous only for population pools which had not previously been exposed to it. He argues that the bacillus can survive in association with communities of burrowing rodents, squirrel like creatures called marmots, which live in vast underground networks of burrows in the steppes of Central Asia. The problem with marmots is that their skins were valued as furs and whilst the Steppe people had either developed an immunity or learned to keep their distance, merchants from other countries, both Eastern and Western wished to trade in marmot fur so marmots, or bits of them, were brought into contact with populations which had not previously been exposed to the plague.
The first known historical outbreak of bubonic plague recorded in China was in 610, but the Byzantine author Procopius described a plague in Byzantine between 542 and 543 which had symptoms very similar to the later bubonic plague. During the period of Mongol dominance a network of commercial caravans routes and military bases linked the Mongol capital at Karakorum with the eastern and western extremities of their empire. The increasing volume of regular human traffic across the steppes infected the burrows of the marmots with pasteurella pestis which remained there, probably from similarly infected colonies in the Himalayas or Burma. From this central position the bacillus could be transmitted east or west travelling with humans by rat or flea. The speed with which it could be transmitted would depend upon the life expectancy of the fleas and rats carrying the disease and the rapidity with which they were transported to population centres via the trade routes, and especially by ships which carried their own resident colonies of black or brown rats in sufficient numbers to provide living hosts for the bacillus until such time as it reached a port where the rats could get ashore and infect the local rat, and human, population. This is open to debate. However the fact that the outbreak of bubonic plague in 6th century Byzantium did not spread into Europe is probably significant. Although C6th Byzantium was a major population centre its links with the Western Europe were much more tenuous, so the plague could get to Byzantium either from central Asia, or via the Middle East, but did not spread further west because there was neither the density of population nor the frequency of maritime communication to allow the primary vectors of the plague to survive an extended journey. From the point of view of the bacillus the world ended at the Dardanelles. By the fourteenth century the population density of Europe was as high in some places as it was to be in the nineteenth century, and major cities in the Mediterranean traded regularly and swiftly by sea with the Black Sea trading centres which were way stations for goods and diseases travelling across the Steppes of Central Asia en route for the markets of the West. Fourteenth century Europe was thus uniquely vulnerable to the plague. The combination of population growth, fed by apparently successful agrarian systems, stimulated sophisticated trading networks stretching through the Mongol Empire across central Asia and into Russia. All of this opened the channels of communication through which pasteurella pestis could strike across Europe. Once established it recurred from time to time, but it did not find in Europe any colony of burrowing rodent hosts with which it could establish a symbiosis and therefore it never became endemic. Every recurrence entailed the reestablishment of a link with the endemic colonies in the Steppes of Central Asia. There were a number of other reasons why Europe was vulnerable to the plague but we will come onto those later. Historians do not entirely agree about the nature of the plague, in spite of the recognisable symptoms. One problem is the speed of dissemination which some argue was faster than could have been achieved with existing means of transport. One factor which made possible the transmission of the plague from Central Asia to the ports in the Black Sea was the use by the Mongols of swift mounted forces and relays of couriers who could cover over a hundred miles in a day. We can assume that those fleeing from the plague in European ports carried the fleas inland in the same way. However Geoffrey Twigg has argued that the plague spread too fast and the death rate was too high for a mere vector borne bacillus and that the livid blotches and black skin lesions characteristic of the diseases could also be symptoms of Anthrax. Anthrax is a much more deadly disease disseminated not by vectors like the flea but by airborne spores. The dormancy of anthrax spores in buildings, for example, might be used to explain the recurrences of the plague between 1348 and the sixth outbreak in 1410. Twigg’s argument is worth considering but is unlikely to be correct. We should remember that during the first phase of the 1348 plague an estimated 30% of the population of Europe died, either from the plague or from associated diseases. Put the other way round 70% of the population of Europe survived the plague, and there were places, especially Poland and Bohemia, which it did not reach at all. Its primary channels of communication can be related fairly closely to the primary trade routes, especially the waterways. Anthrax distributed on the wind would have travelled faster and more indiscriminately, but more importantly anthrax is a serious killer which does not depend on zoological vectors, ie., it does not need intermediate hosts like rats and fleas. An outbreak of anthrax sufficiently virulent to kill off 30% of the population would almost certainly have killed off most of the population and it would have remained active for generations afterwards to kill off any survivors. However this is a question which you might like to discuss in tutorials.
So much then for the nature of the plagues of the fourteenth century. There is, of course, a great deal of detail which you must supply for yourselves.
