Environment, Society and the Black Death

by Desconhecido

  Fig. 38. Excavation plan showing the distribution of single, double and triple graves at the plague cemetery Holje, Jämshög village, in the province of Blekinge, from 1710

  In conclusion, most victims of the Black Death as well as of later plague epidemics were probably buried in ordinary cemeteries. In large and densely populated towns of Europe, special plague cemeteries were established, which contained single graves, multiple graves and mass graves. However, the only safely identified plague cemetery in Sweden was established in connection with the last plague epidemic of 1710–13. It followed a new national regulation, according to which the burial of plague victims on ordinary cemeteries was no longer allowed. We cannot exclude the possibility that some plague cemeteries, and even mass graves, were established in Sweden also before, for instance in connection to the Black Death. But based on present knowledge, the best place to search for the victims of the Black Death is probably in the ordinary medieval cemeteries. Indications to look for may be accumulations of single graves as well as multiple graves with two, three or more individuals. Hopefully this can be tested in the future by more thorough chronological and stratigraphic studies in combination with aDNA analysis.

  Stature – a health parameter through history

  Stature varies greatly among individuals and around the globe, and it has also varied significantly through history. Long-term changes may be studied first of all by osteometric analysis of skeletons from different periods, while written records may also contribute with statistics for the last few centuries. In Sweden the earliest systematic records derive from the nineteenth century and the conscription of soldiers. Based on this combination of sources and methods we have a fairly clear picture of the long-term trends in stature in Scandinavia.57

  Fig. 39. Triple grave containing one adult woman, one young person (14–18 years) and one child (4–5 years). The plague cemetery in Holje, Jämshög village, Blekinge, from 1710 (photo: Bengt Jacobsson)

  People living in the nineteenth century were short, actually as short as the hunter-gatherers who lived in Sweden 6000 years ago. But between these two low points stature has varied considerably, and during the Roman Iron Age (first to fourth centuries AD) people were almost as tall as we are today.58 From the Roman Iron Age to the eleventh century average stature decreased by 5 cm. During the Middle Ages there were relatively small changes (see our new results below), until stature started to decrease steadily to reach a nadir in the mid-nineteenth century. Since then, stature increased again to reach present-day values.59 This increase was very sharp. In only 150 years, average stature of men in Europe increased by 11 cm, which is the fastest change recorded so far (Fig. 40).60

  What are the causes behind the long-term fluctuations in stature through history? According to studies of modern living populations, stature depends on both genetic factors and on living conditions and lifestyle. Particularly important are living conditions that affect the mother during pregnancy and child during the early years of childhood.61 Factors that have been proved to influence living conditions are social class,62 income and education,63 environment (urban or rural) and family size,64 which in turn can affect nutritional status and exposure to infectious diseases. Hence, stature is affected by a multitude of social factors, and may be used as a general indicator of the average living conditions in a society.65 It is used today by WHO as a sensitive health indicator and a measure of the nutritional state within a population.66

  Fig. 40. Diagram showing the increased stature of men in some European countries during the last 150 years (based on data from T. J. Hatton 2013)

  Regarding the connection between stature and food intake, the nutritional composition is considered to be a more decisive factor than the amount of food. In general, there is a relationship between protein intake and stature, and particularly animal protein, fat, vitamin, essential fat and amino acids are vital substances concerning growth.67 Studies of the population of Japan, which has undergone a marked increase in stature during the last 50 years, indicate that an important underlying cause to the observed increase in stature is a larger intake of animal protein and energy.68 In this case it is particularly connected to an increased intake of milk products.69 Also the marked increase in stature in Europe during the last century is considered a reflection of better living conditions, together with improved control of diseases and decreased infant mortality.70 It has also been shown that it could not be explained by genetic evolution.71

  In other words, the scientific community agree that changes in stature in a population are strongly linked to living conditions (lifestyle, health and welfare), and we may therefore use it as an indication also of living conditions in the past. In this section medieval stature will be discussed, and the focus will be on possible changes in living conditions in connection to the Black Death and the associated population drop.

  Estimations of stature presented here are based on length measurements of femur (thigh bone) according to standard protocols.72 Two different femur measures have been used – maximum length (M1) or physiological length (M2). To be able to compare all the materials, comparison is based on the estimated stature, not on the femur measurements.73

  The skeleton data collected for this study derive from cemeteries in different environmental settings and from different periods of the Middle Ages (1050–1536). Some materials are older while others are younger, so that the total period covered by the study is c. 990–1620. From this period approximately 16,500 skeletons have been analysed and of these stature has been estimated for 4876 adult individuals deriving from 65 different cemeteries. Geographically the cemeteries are distributed over a large part of present-day Sweden, from the province of Jämtland in the north to Scania in the south, and from Västergötland in the west to the Baltic island of Gotland in the east (Fig. 41). However, the majority are from Östergötland and Scania. These two provinces are today densely settled, and the high number of investigated cemeteries partly reflects the intensity of archaeological activity in connection to exploitation, but they were also the most heavily populated during the Middle Ages. All the cemeteries are from within the borders of present-day Sweden, but several of them are from provinces that belonged to Denmark during the Middle Ages (see Appendix 2 for details).

  Fig. 41. Map of Sweden showing sites with osteological materials used in the present study. Numbers refer to Appendix 2.

  The major goal was to find materials to compare stature before and after the Black Death in 1350 and therefore chronology was essential. The different materials have been dated using different methods, such as dendrochronological dating of the coffins, radiocarbon dating, stratigraphy, the position of arms (which varies over time) and written sources. Many of the medieval cemeteries have been in use for several hundred years. For most of the cemeteries with such a long history, it has not been possible to make any fine chronological distinctions. Only at Trinitatis in Lund, which covers the time period 990–1536, have several different phases of the Middle Ages been distinguished within one and the same cemetery (see above).74 It enables comparison between populations from the same area through time. In addition, cemeteries with a shorter history have been most valuable. Several of the medieval cemeteries were in use only before the Black Death, whereas others cover only the period c. 1300–1536. Very few new cemeteries were established after 1350. For the most part, the establishment of cemeteries reflects overall population development. When population numbers were drastically reduced after the Black Death there was no need to establish new cemeteries, not until a few centuries later when new towns were founded.

  Hence, there are few medieval cemeteries that exclusively represent the period after 1350 and they are mainly from later periods. Some of them are from special circumstances, like the executed individuals buried at St Michael in Lund, the execution places like Slottsvången in Helsingborg and Galgberget in Vadstena, and the mass grave from the battle of Good Friday in Uppsala. There are also two ordinary cemeteries from after 1350 –
St Gertrud in Visby and the Nya Lödöse cemetery.

  Materials from Helgeandsholmen in Stockholm and St Jörgen in Malmö were initially regarded as post-Black Death materials based on previous publications.75 However, the dating of the establishment of these two cemeteries is uncertain. Finds of several graves containing 2–5 individuals, which may be plague victims, indicate an establishment already by the time of the Black Death.

  The material does not only represent different periods and different geographical areas, but also different social classes. Ordinary parish cemeteries can be expected to represent all social categories, whereas monasteries, convents, military mass graves, execution places, sanctuaries and hospitals reflect different parts of society (Appendix 2). In monasteries and convents many of the buried were monks or nuns, but the majority were wealthy people from outside.76 The monastic orders represented are Dominican Black Friars and Cisterciensians. The monks and nuns of Dominican Black Friars survived through almsgiving and were not allowed to own property, while the Cisterciensians and Premonstratenser were landowners, sometimes with numerous farms and very large estates. The materials from the monasteries and convents span the whole period c. 1100–1536.

  In the military mass graves are found professional soldiers but also peasants. Only occasionally, when they ended up in the grave wearing their armour, can professional soldiers be distinguished from other men.77 Skeletons from execution places represent a mixture of individuals from different parts of society.78 According to the written sources, 90% of those who were sentenced to death were convicted for murder, theft or adultery. But people who had committed suicide were also buried at the execution places. In cemeteries belonging to sanctuaries and hospitals, finally, we find the sick who stayed at these institutions for medical treatment, but also elderly who used the sanctuaries as a place of retreatment.79

  Fig. 42. Stature distribution of men and women from (a) convents and monasteries and (b) ordinary parishes

  To test if different life conditions due to social status is reflected in stature, not only today but also in medieval populations, monasteries and convents were compared with ordinary parish cemeteries. It is known from written records that monastery and convent cemeteries were not only for the brothers and sisters, but particularly for people who could afford to buy a grave there. If these wealthy people had experienced better life conditions and eaten a more well-nourished diet than common people, it may be expected that they would be taller than average. The material from ordinary parishes consisted of 4052 individuals (1502 women and 2550 men) and the material from monasteries and convents of 815 individuals (292 women and 523 men). Interestingly, both women and men buried in monasteries and convents were significantly taller than those buried in the ordinary parish cemeteries. Mean values for women and men in monastery and convent cemeteries were 161.6 cm and 173.3 cm, whereas women and men in parish cemeteries measured 160.4 cm and 171.7 cm, respectively (Fig. 42; Table 1). The difference is significant for both women and men,80 indicating that stature could be used as a parameter for social difference during the Middle Ages.

  Table 1. Estimated stature for different populations and time periods

  Several authors have argued that living conditions improved after the Black Death.81 There may have been several reasons for this. One may simply be that the most poor and under-nourished died from the plague. The most common explanation, however, is that the smaller population resulted in a shortage of labour, which after a period of conflicts and resistance resulted in higher wages and lower rents and taxes. This resulted in higher popular consumption and better living conditions for the majority of ordinary people. According to another line of reasoning, the shortage of manpower and excess of land in agriculture after the population drop resulted in a gradual shift from crop growing to animal husbandry.82 The pollen record presented in Chapter 4 indicated that such a shift actually happened, at least in marginal uplands. An expected consequence of increased animal production would be an increased consumption of meat and milk products. However, documentary sources provide very little information on the consumption of food among ordinary people in medieval Sweden.

  If living conditions improved after the Black Death and if the consumption of meat and milk products increased, it may show up in stature. To test this it is important to distinguish between population from before and after the Black Death. Of the 65 cemeteries (also including execution places and military mass-graves), 24 (39%) were in use only before the Black Death and seven (11%) only after. From the first group stature has been calculated for 727 women and 1408 men, and from the second and much smaller group, for 53 women and 126 men. Based on these populations, mean stature for women was 160.2 cm before the Black Death and 162.7 cm after. For men mean stature was 171.5 cm before the Black Death and 172.5 cm after (Fig. 43; Table 1). Hence, both women and men show a slight increase in stature after the Black Death, but only for women is the change statistically significant.83

  Apart from changes in mean stature, the frequency of really tall individuals – that is to say women taller than 170 cm and men taller than 180 cm – was also higher after the Black Death. The relative number of tall women increased from 3.9% to 9.4%, whereas the relative number of tall men increased from 8.9% to 12.7%.

  It can be concluded that there was no decrease in stature after the Black Death, and therefore no indication that living conditions got worse. On the contrary, there was an increase in stature indicating improved living conditions, although the change is statistically significant only for women. Also the number of very tall increased, both among women and men. A limitation is the rather small sample after the Black Death.

  Figure 43. Stature distribution of men and women from (a) before and (b) after the Black Death

  Fig. 44. Diagrams showing changes in mean stature for men and women in Sweden 1000–2000. Medieval stature before and after the Black Death is based on the present study, 1710 stature is based on a skeletal plague material published by Arcini et al. (2006), 1850 stature is based on measurements on living population (Hultkrantz 1927) and so is present-day stature (Gustafsson et al. 2007)

  A similar comparison of stature was made based on only the material from Trinitatis in Lund. In this cemetery a tentative distinction has been made between graves from before and after the Black Death (see Fig. 36). According to this distinction, mean stature for women was 160.7 cm before the Black Death and 161.2 cm after, hence a small increase. However, mean stature for men decreased from 172.0 cm to 170.8 cm (Table 1). None of the changes is statistically significant.84 When looking at the relative number of very tall people, contrary to the result from the larger study, they became fewer in the Trinitatis material after the Black Death. However, the tallest man in the entire material is one individual from after the Black Death in Trinitatis. He measured 199.9 cm.

  The fact that stature seems to have increased more for women than for men – both in the total material and in the material from Lund – indicates that the height difference between the sexes was reduced after the Black Death. Possibly women in particular benefited from improved living conditions.

  Two other populations that may be compared are the two military mass graves. The majority of those who died in the Battle of Visby were ordinary farmers from the island of Gotland and some were Danish soldiers. The battle took place in the summer 1361, which means that they must have been born and raised before 1350. Possibly they were stronger and better fed than average because they had obviously survived the Black Death as well as the plague of 1359–60. The Battle of Good Friday in Uppsala took place in 1521. In this case also there were both farmers and professional soldiers among the dead. They were born around the turn of the century, 1500, after the nadir of the late-medieval crisis in a time when society had slowly started to recover. These two military mass graves represent two comparable groups of men born and raised before and after the Black Death.

  The mean stature for men who died in the Battle of Visby was 172.0 cm and 9
% of them were taller than 180 cm (Table 1). The men who died in the Battle of Good Friday show a mean stature of 173.6 cm and 14.7% of them were taller than 180 cm. Hence, the comparison shows that the later population was slightly taller, but again the difference is not statistically significant.85 However, this is yet another indication that there was a slight increase in stature after the Black Death.

  The new results on medieval stature are put in a longer time perspective in Figure 44. As evident from the figure, the increase in stature after the Black Death was only temporary. After the end of the Middle Ages, stature started to decrease again to reach a low-point in the mid-nineteenth century, before it increased strongly during the twentieth century. The long-term development was similar for men and women.

  Changes in diet?

  Written sources indicate that the supply of food products may have changed after the Black Death. As mentioned above, agricultural production changed not only in quantity but also in composition and in particular animal husbandry seems to have increased in importance, at least in some regions.86 However, written sources on food habits are restricted to monasteries, convents and the ruling classes of society. If we want to study food consumption among ordinary people and to look for possible changes in diet other methods have to be used. During the last decades new methods have made it possible to study the palaeodiet of individuals by stable isotope analysis.

  Stable isotope analysis for palaeodietary reconstruction is based on the principle that the isotope composition in body tissues of both animals and humans reflects the isotopic composition of the food they have eaten. In the present study the isotope compositions of carbon and nitrogen have been measured, which are particularly useful in this context.87 For carbon, δ13C (the ratio between 13C and 12C expressed in ‰) reflects the relative amount of proteins from marine food sources (marine fish, shellfish, seals, seabirds) in comparison to terrestrial. For nitrogen, δ15N (the ratio between 15N and 14N expressed in ‰) reflects the relative amount of proteins from animal products (meat, milk products, eggs, fish, shellfish) in comparison to plant products (vegetables, cereals, beer, etc.). However, different types of plants may also result in different δ15N. Furthermore, when it comes to animal products, δ15N is affected by the trophic level, i.e. the position in the food chain, so that food derived from higher trophic levels results in higher δ15N in human tissue.88 Other factors may also influence the isotope values.89 When interpreted in relation to the isotopic signatures of available food sources, the combination of carbon and nitrogen isotope ratios in archaeological bone provides a proxy of the diet of an individual. It is important to note, however, that it reflects only the main protein sources and not the diet as a whole.90