Environment, Society and the Black Death

by Desconhecido

  For this study the material from the Trinitatis cemetery in Lund, dated to 990–1536, was chosen, which allows a comparison before and after the Black Death. The study is based on teeth from 99 adult individuals representing five different phases of the Middle Ages (Appendix 3).91 In the selection of individuals for sampling, three criterions had to be fulfilled: well-preserved teeth (first molar, incisive and second molar), femur length measurements and sex identification. To also investigate the possible relationship between dietary composition and stature in the studied population, the skeletons of the longest and shortest individuals that fulfilled these three criteria were also selected for analysis. By using teeth the diet signal of the child is caught, which is important since diet during childhood affects adult stature. The results are presented for the 99 individuals (46 men and 53 women) in Appendix 3.

  The stable isotope values in the whole material irrespective of time period range for δ13C from -22.3‰ to -18.7‰ (average -19.9%) and for δ15N values from 8.1‰ to 14.6‰ (average 11.6‰). The results indicate that nearly two-thirds of the individuals acquired a certain part of their nutrition from the sea. The distance between Lund and the coast was not far and findings of fishing gear in the oldest settlement of the town indicate that fish may have been brought to the city with fishermen who lived there.92 Osteological analyses of fishbone from Lund show that consumed fish consisted mainly of cod, although herring dominated during some periods and also flounder was common from time to time. Freshwater or brackish-water fish, with few exceptions, was not on the menu very often, but when it did it consisted of roach, perch and pike.93

  A closer look at the results from the different periods indicates clearly that there was a change in diet. However, this change did not happen when might be expected, i.e. in connection with the Black Death, but some centuries earlier, around 1100. As evident from the diagrams in Figure 45, there are several individuals with very low nitrogen values from the period 990–1100, but not from later periods. No less than one-third of the individuals from the early period display δ15N values between 8.1‰ and 9.8‰. Depending on these low values, the average δ15N value for that period is only 10.5‰. It is significantly separated from the later phases of the Middle Ages,94 which show average δ15N values between 11.9 ‰ and 12.2‰. However, the early period shows a great variety of values and one third of the individuals have relatively high nitrogen values, between 11.0 and 14.0.

  How then should the different nitrogen values from Lund be interpreted in terms of diet composition and possible change in diet? The individuals with low nitrogen isotope values in the early period (990–1100) probably had a diet based primarily on cereals. A similar pattern, with unusually low nitrogen isotope values in an early phase of the town, was noted also in the medieval town of Sigtuna, in the province of Uppland. In that case also the low values were interpreted as an indication of a high relative input of cereals and vegetables.95 A closer look at the material from Lund reveals that all the individuals with low nitrogen values were buried in a peripheral part of the cemetery, and the burial custom indicates that they had something in common as a group.96 Because the peripheral part of the cemetery during the Middle Ages was generally reserved for the poor, the low nitrogen values probably reflect low social status. The buried individuals may have been slaves or other poor people with a lower consumption of meat than other social groups.97 Hence, the great variety in isotope values in the earliest phase of Lund may reflect strong social stratification. The increase of mean nitrogen isotope values after 1100 reflects an average increase in the relative intake of meat or other animal products. This change was probably due to the disappearance of the very poor and may hypothetically be associated with the gradual termination of slavery.

  The observed variation in diet is however not reflected in stature. In Figure 46, δ15N‰ is plotted against femur length, where δ15N‰ is used as a proxy for the relative amount of animal proteins in the diet and femur length as a proxy for stature. The two parameters show no correlation. This may be explained by the fact that also other living conditions than diet affects stature, and that δ15N‰ does not catch all the dietary factors of importance. For instance, even though it reflects the protein composition, it says nothing about the amount of protein intake, or for that matter the amount of food.

  Migration and stature

  The medieval town of Lund was, like many other urban centres, a magnet that attracted people from different places. The intensity of migration has of course varied over time for various reasons. To test if observed variations in stature could be related to migration, it was decided to examine mobility as another characteristic of the population. The aim was to see if migration to the town changed over time and specifically following the Black Death when cities were likely in need of labour. Strontium isotope ratios in tooth enamel were used to investigate this question.

  Isotopic ratio of strontium has been used in a number of studies for proveniencing human remains. The isotope ratio of interest is 87Sr/86Sr. The basic principles are straightforward. 87Sr/86Sr varies among different types of rock and enters the human body through the food chain as nutrients pass from bedrock through soil and water to plants and animals. Strontium substitutes for calcium in the hydroxyapatite mineral of skeletal tissue and is stored there. Human tooth enamel forms during the first years of life and remains unchanged during life and often long after death. Isotopes of certain elements (strontium, lead, oxygen) vary in amounts according to geography and are deposited in tooth enamel as it forms. Thus, tooth enamel retains an isotopic signal of the place of birth. If that signal differs from the place of burial, then the individual must have moved during his/her lifetime. The application of strontium isotopes in a variety of archaeological settings has revealed significant movement in the past.98

  Fig. 45. Carbon and nitrogen isotopic ratios for humans in medieval Lund (Trinitatis Cemetery) during different time periods. AD 1350/70 includes possible Black Death victims

  Fig. 46. Nitrogen isotopic ratios and femur length for men and women in Lund during the Middle Ages. No correlation between the two parameters was found

  Fig. 47. Bedrock map of the province of Scania

  Fig. 48. Map of Scania with 87Sr/86Sr baseline values from archaeological studies. Values between 0.710 and 0.711 are mainly found in south-western Scania and values above 0.712 are rare

  87Sr represents approximately 7% of total strontium in nature and 86Sr around 10%. Thus, the measured 87Sr/86Sr ratio has a value in nature between approximately 0.703 and 0.750, and sometimes higher. While the range of these numbers may seem small, 87Sr/86Sr ratios can be measured very accurately to the sixth decimal place and have been used by geologists for many years to characterise and date rock formations. These isotopic ratios work well for identifying non-local individuals in a population but identifying the place of origin is more difficult because similar isotopic ratios are often found in a number of locations.

  Although a potential complication of strontium isotope analysis in bioarchaeology is post-burial contamination (diagenesis), tooth enamel is generally resistant to diagenesis and may be relatively well preserved even when bones are contaminated.99 In any case, a non-local isotopic signature is always significant because ‘contamination’ is a local signal. Hence, diagenesis does not result in the misidentification of locals as immigrants. It is also important to note that the analysis can distinguish only first generation migrants, not their offspring. In a community occupied for several generations, only a small proportion of the individuals in a cemetery might be from the first generation.

  An essential issue in strontium isotope analysis involves determination of the local strontium isotope signal for the area in which a burial is found. Measurement of these baseline values is essential for identifying non-local individuals.100 The local bioavailable isotopic signal of the place of burial can be determined in several ways: in human bone from the individuals whose teeth are analysed, from the bones of other humans
or archaeological fauna at the site, or from modern fauna, water, soil extracts or vegetation in the vicinity.101

  The province of Scania has varied bedrock, characterised by old granites and gneisses in the north and east, and much younger bedrock primarily composed of marine sediments such as limestone and chalk in the southwest (Fig. 47). The bedrock has varied strontium composition, which is reflected in bone material from archaeological sites. Information is available from several archaeological studies of strontium isotope ratios in southern Sweden,102 and the data from Scania are summarised in Fig. 48. In general values between 0.710 and 0.711 are found in southwestern Scania and range somewhat higher to the north and east. Values above 0.712 are rare.

  Bioavailable samples from cattle and pig tooth enamel have also been examined from the nearby site of Uppåkra,103 located about 5 km south of Lund. There are slight differences between the two species. The mean value for 14 cattle teeth was 0.7118±0.0009 with a range 0.7097–0.7134. The mean value for six pigs was 0.7115±0.0002 with a range 0.7113–0.7118. The very low variance for the pigs suggests that this range of values likely reflects the local value at Uppåkra. The variation among the cattle, particularly one very low and two very high values, suggests that some of these animals were imported. Finally measurements from two faunal samples from Lund itself were used – archaeological specimens of black rats – with 87Sr/86Sr values of 0.7112.

  In order to examine changes in mobility over time, burials were sampled from the parish cemetery of Trinitatis, presented above. Strontium isotope ratios were measured in tooth enamel from 74 adult individuals (36 male and 38 female),104 and these values had a mean of 0.7116 (±0.002) with a range 0.7082–0.7191 (Appendix 3). The strontium isotope ratio results are presented in a rank-ordered bar graph in Figure 49. The local baseline appears quite clear in this graph and includes all the individuals with values between 0.710 and 0.712. Approximately 37% of the analysed individuals are indicated as non-locals, with 11/74 below 0.710 and 17/74 above 0.712. The variation in 87Sr/86Sr values indicates that nonlocal individuals came from several different places. A kernel density plot105 clearly shows this multi-modality in the values (Fig. 50). Kernel density estimates are a data smoothing technique that reduces the problem of interval size in standard histograms.106 The plot shows a primary mode between 0.710 and 0.712 within the local range. A slightly lower mode below 0.710 may represent individuals from elsewhere in southwestern Scania, Denmark, or northern Germany. The small modes above 0.712 reflect individuals from a variety of different places in the older geological terrain elsewhere in Sweden or northern Scandinavia.

  Regarding changes in mobility over time, the highest rate of non-locals appears in the earliest period of the history of Lund, the establishment phase (Fig. 51). That greater variation in strontium isotope ratios occurred during the earliest period of the city is not surprising. Lund was founded in the late 900s during the reign of King Sven Forkbeard on a royal initiative to serve as an administrative and religious centre for eastern Denmark. It was populated by priests, administrators, soldiers, merchants, and workmen of all kinds – minters, artisans, goldsmiths, blacksmiths, comb makers, shoemakers and slaves. Burial customs like different types of coffins, charcoal, and chalk in the graves, finds of coins as well as written sources indicate that among the buried were men and women from England, Germany, the Slavic area and of course parts of present-day Denmark.107

  Variation then declined and of particular note is the absence of non-locals during the period of the Black Death, from 1350 to 1370. A medieval town like Lund usually harboured people from both far and near. Most of them were temporary visitors who came there for trade. The strontium results indicate that this exchange with a wider surrounding broke down during the plague. At the same time we see that Lund in the period after the Black Death once again exhibited increased immigration and that the contacts with a wider world were resumed. Perhaps it indicates that the city had need for labour in the wake of the plague.

  Lessons from the last plague 1710–1713

  In Sweden there are few written sources from the time of the Black Death but more plentiful records from later plague epidemics. Particularly from the last plague of 1710–1713 there are detailed records that shed light on how plague spread and how the local society reacted. The most useful records are church books containing information about when the plague appeared in the parish, how many died, and sometimes also the sex and age of the diseased. They also provide data on the number of births and marriages.108

  The last plague may tentatively be used as a reference for the Black Death. There are several reasons for this. In the early eighteenth century, when Sweden was struck by the plague for the last time, the country was not much more densely populated than at the time of the Black Death in the middle of the fourteenth century. In the area covered by present-day Sweden, the population in the mid-fourteenth century before the Black Death and in the beginning of the eighteenth century was approximately 1.1 million and 1.4 million, respectively.109 In the early eighteenth century the majority of the population still lived in rural areas. Furthermore, agricultural systems were not very different from the medieval ones.

  Fig. 49. Ranked 87Sr/86Sr values of two fauna samples (black) and 77 human samples (blue) from Lund. Red band marks the estimated local baseline range at Lund. The human samples are from the Trinitatis Cemetery

  Fig. 50. The Kernel Density plot of 87Sr/86Sr values from human tooth enamel from Lund shows a primary mode between 0.710 and 0.712 within the local range. A slightly lower mode below 0.710 may represent individuals from elsewhere in south-western Scania, Denmark, or northern Germany. The small modes above 0.712 reflect one or a few individuals from a variety of different places in the older geological terrain elsewhere in Sweden or northern Scandinavia

  Fig. 51. Strontium isotope ratios from Lund ranked by time period. Red band marks the estimated local baseline range at Lund

  The most important difference between the fourteenth century and the early eighteenth century was the very different preparedness to plague. When the Black Death struck Sweden in the fourteenth century there were only religious precautions. In letters to the dioceses in the autumn of 1349, Magnus Eriksson, king of Norway and Sweden, warned of a disease with great mortality that was approaching Sweden.110 King Magnus dictated that all the people of Sweden, clerks and lay people, old and young, women and men should every Friday come barefoot to the church, hear the mass and on the alter sacrifice a coin (a penning) or less according to ability. Everyone should fast every Friday on bread and water, not even eat fish, lean their conscience and humbly do penance and repent of their sins. He hoped that this would make God turn the plague from them. When the last plague struck in the early eighteenth century, it was no longer seen only as a divine punishment for human sin, but as a phenomenon that could be prevented and limited by human countermeasures. Sweden had experienced several plague epidemics since the devastating Black Death and now authorities were more on guard and regulations were more developed. However, in spite of the better preparedness, 200,000 Swedish citizens died.

  In southern Europe regulations intended to stop the plague were established earlier than in Sweden, in some places already in connection with the Black Death. In 1348 special health commissions were established in the Italian cities of Venice and Florence, and in Ragusa (present-day Dubrovnik) 30 days of quarantine for incoming ships was stated in 1377.111 In 1370 the authorities of Milan and Mantua prohibited all contact with areas that were contaminated by the Black Death,112 and from later plagues in the fifteenth and seventeenth century they imposed health passports in order to stop the rampage of the disease.113 Sometimes these countermeasures were taken too late, when local authorities tried to deny and underplay the arrival of plague in their town.114 In Sweden the earliest evidence of quarantine regulations are from a plague epidemic in 1577, and in 1638 the death penalty was imposed on those who broke the isolation rules.115 In Denmark the first regulations intend
ed to protect the population from plague came in the second half of the sixteenth century.116

  However, in her study of the plague in Scania 1710–1713, Bodil Persson showed that despite proclamations and rules from the authorities, people continued to gather at burials and in houses where people had died of plague, to mourn the diseased and to share the belongings. Also during times of plague, people gathered not only for burials but also for other religious traditions like marriage and baptism.117 Obviously, new regulations could not easily change deeply rooted cultural behaviour, customs and traditions. When authorities, in November 1710, declared that plague victims should no longer be buried in the ordinary cemeteries but in special places far away, people refused to accept it. Priests were threatened by their parishioners and forced to break the regulations, and in some cases relatives dug up their dead and dragged them in to the graveyards.118 To get a decent burial on sacred ground was as important in the eighteenth century as it was during the Middle Ages.119