All posts by Richard Thomas

re: Livestock size change in the 14th century

For a little while now, I have been interested in identifying and explaining changes in the size of domestic livestock in the 14th century. This research was originally inspired by my analysis of the animal remains from Dudley Castle, West Midlands, UK, which revealed a statistically-significant increase in the size of cattle, sheep, pig, and even chicken, between two phases of occupation (1262-1321 and 1321-1397). These changes were much earlier than those documented at other sites (mostly 15th-17th century), and I interpreted them  within the context of altered tenurial and agricultural practices in the wake of the Black Death: Thomas, R. 2005. Zooarchaeology, improvement and the British Agricultural Revolution. International Journal of Historical Archaeology 9 (2): 71-88.

Since then, a number of additional sites have provided evidence of livestock size change in the 14th century – seemingly adding weight to this idea. Just recently, however, I have completed a collaborative project exploring size change in domestic livestock in medieval and early modern England, using data from London: Thomas, R., Holmes, M., and Morris, J. 2013. “So bigge as bigge may be”: tracking size and shape change in domestic livestock in London (AD 1220-1900). Journal of Archaeological Science 40 (8): 3309-3325.

In this study, we analysed 7966 individual cattle, sheep, pig and chicken bone measurements from 105 sites excavated in London dating to the period AD 1220–1900 and multiple episodes of size change were identified. The earliest evidence for size change in cattle and sheep occurs in the early 14th century: this is earlier than any previously documented instance of livestock size increase in the medieval period. The fact that only cattle and sheep witness size increase is interesting, given the major outbreaks of disease affecting these animals in the first quarter of the 14th century: sheep murrain was epidemic between 1314 and 1316, while a panzootic in cattle occurred between 1319 and 1322. Given the timing of the size increases and the fact that only cattle and
sheep are affected, re-stocking policies might be an obvious explanation. However, selective breeding from larger animals was probably not the cause: there is no zooarchaeological evidence for large livestock elsewhere in England and Wales in this period and the large-scale transnational cattle trade did not commence until the late 15th century. Perhaps, a temporary relative increase in mean size may have
occurred in the archaeological (death) assemblage, because of relatively lower slaughter rates of female cattle following the pestilence. This might be explained by the
fact that the slaughtering of females, which survived the panzootic, might have been delayed, to re-populate the herds; consequently, survivors were used for a longer period than would have normally been the case. Alternatively, the larger size of cattle and sheep may reflect the actions of natural selection. It is entirely conceivable that smaller, weaker animals were more susceptible to malnutrition and ultimately mortality, while the larger, healthier animals survived to perpetuate their genes.

At the moment I am fairly open about the most likely explanation, but I would welcome any thoughts if you have any.

Rats cannot have been intermediate hosts for Yersinia pestis during medieval plague epidemics in Northern Europe

Journal of Archaeological Science

Volume 40, Issue 4, April 2013, Pages 1752–1759

Rats cannot have been intermediate hosts for Yersinia pestis during medieval plague epidemics in Northern Europe

  • a University Museum of Bergen, University of Bergen, Norway
  • b Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, P.O. Box 1103 Blindern, N-0317 Oslo, Norway


The commonly accepted understanding of modern human plague epidemics has been that plague is a disease of rodents that is transmitted to humans from black rats, with rat fleas as vectors. Historians have assumed that this transmission model is also valid for the Black Death and later medieval plague epidemics in Europe. Here we examine information on the geographical distribution and population density of the black rat (Rattus rattus) in Norway and other Nordic countries in medieval times. The study is based on older zoological literature and on bone samples from archaeological excavations. Only a few of the archaeological finds from medieval harbour towns in Norway contain rat bones. There are no finds of black rats from the many archaeological excavations in rural areas or from the inland town of Hamar. These results show that it is extremely unlikely that rats accounted for the spread of plague to rural areas in Norway. Archaeological evidence from other Nordic countries indicates that rats were uncommon there too, and were therefore unlikely to be responsible for the dissemination of human plague. We hypothesize that the mode of transmission during the historical plague epidemics was from human to human via an insect ectoparasite vector.

Medieval pig management

I have a new paper published that explores the impact of Black Death on pig management…I hope it is of interest.
Hamilton, J. and Thomas, R. 2012. Pannage, pulses and pigs: isotopic and zooarchaeological evidence for changing pig management practices in 14th century England. Journal of Medieval Archaeology 56: 235-260.
Zooarchaeological analysis of a substantial assemblage of animal bones excavated from Dudley Castle, West Midlands, suggests that a significant change in pig management occurred during the 14th century. A dramatic decrease in the relative abundance of pigs, combined with an increase in the size of post-cranial bones and teeth, and a higher proportion of neonatal individuals, raises the possibility that greater control over breeding and feeding was being exerted in this period through the emergence of enclosed husbandry practices. Carbon and nitrogen stable-isotope analysis of a sample of 41 pig mandibles from two tightly dated phases of occupation supports this interpretation. Between the late 13th century and later 14th century there was a statistically significant decrease in δ 15N, but not in δ 13C, and pig dietary diversity probably also decreased. This paper discusses several explanations for these patterns, all consistent with a major change in pig management at this time.

Richard Thomas – zooarchaeologist

My interests in the impact of the Black Death and the 14th-century crises on animal husbandry, diet, and human-animal relations in general, stemmed from my doctoral research (completed in 2002). This research involved the analysis of a large assemblage of animal bones from a castle site located in central England (Dudley Castle), with material dating from the 11th to the mid-18th century. This analysis revealed some major changes in animal exploitation, most especially in the 14th century. Firstly it was apparent that a statistically-significant increase in the size of domestic livestock (cattle, sheep, pig, chicken) occurred in the later 14th century. Other notable changes in this period included increased consumption of wild birds, and altered hunting strategies as the aristocracy sought to maintain social boundaries in the face of social climbers. I have argued that each of these phenomeon reflects socio-economic and environmental consequences of the Black Death (and prior crises of the 14th century). These arguments are laid out in the following publications:

Thomas, R. 2005. Animals, Economy and Status: The Integration of Zooarchaeological and Historical Evidence in the Study of Dudley Castle, West Midlands (c.1100-1750). British Archaeological Reports British Series 392. Archaeopress,Oxford.

Thomas, R. 2005c. Zooarchaeology, improvement and the British Agricultural Revolution. International Journal of Historical Archaeology 9 (2): 71-88.

Thomas, R. 2006. Of books and bones: the integration of historical and zooarchaeological evidence in the study of medieval animal husbandry, pp. 17-26, in Maltby, M. (ed.), Integrating Zooarchaeology. Oxbow,Oxford.

Thomas, R. 2007. Maintaining social boundaries through the consumption of food in medieval England, pp. 130-151, in Twiss, K. (ed.), The Archaeology of Food and Identity. Center for Archaeological Investigations Occasional Publication No. 34,Carbondale.

Thomas, R. 2007. Chasing the ideal? Ritualism, pragmatism and the later medieval hunt, pp. 125-148, in Pluskowski, A. (ed.), Breaking and Shaping Beastly Bodies: Animals as Material Culture in the Middle Ages. Oxbow, Oxford.

More recently, I have begun to further develop some of these ideas. Analysis of pathology in the lower limb bones of cattle, has demonstrated that the cattle of the later 14th-century were being worked much harder than they were in the late-13th-early-14th century and in later periods. Perhaps this was a consequence of the increased demand on cattle for traction following the losses of the cattle panzootic, which resulted in a loss of 62% of cattle in manors in England (Slavin, P., in press. The great bovine pestilence and its economic and environmental consequences in England and Wales, 1310-50, Economic History Review):

Thomas, R. 2008b. Diachronic trends in lower limb pathologies in later medieval and post-medieval cattle from Britain, pp. 187-201, in Grupe, G., McGlynn, G. and Peters, J. (eds.), Limping Together Through the Ages: Joint Afflictions and Bone Infections. Documenta Archaeobiologiae 6: 187-201.

Stable isotope analysis of large samples of cattle and pig bones, is also beginning to support the view that animal diet and management was altered in the aftermath of the Black Death:

Fisher, A. and Thomas, R. in press. Isotopic and zooarchaeological investigation of later medieval and post-medieval cattle husbandry at Dudley Castle, West Midlands. Environmental Archaeology 17 (2)

Hamilton, J. and Thomas, R. in press. Pannage, pulses and pigs: isotopic and zooarchaeological evidence for changing pig management practices in 14th-century England. Journal of Medieval Archaeology 56: 235-260.

Such studies also question the reliability of assuming that stable isotope values in animals are unchanging. This is a critically important consderation for making interepretative sense of isotope values in human skeletal remains.

Most recently I have been involved in a City of London Archaeological Trust funded project which has revealed further evidence for increases in livestock size in the 14th century. When the Dudley Castle data were first published, there were no comparatively early medieval sites in England at which size change in livestock had occurred; the majority of other sites had shown increases one or two centuries later. This  project, undertaken by myself in collaboration with Dr. Matilda Holmes (University of Leicester), and Dr. Jim Morris (Museum of London Archaeology/University of Central Lancashire), has involved a systematic temporal and spatial analysis of archived measurements of cattle, sheep, pig and domestic fowl bones from archaeological sites in London from sites dating 1200-1900. We are currently just writing up the results, but key findings include two phases of size increase in the 14th century, which may well be connected to the impact of the sheep and cattle plagues of the first quarter of the century and an altered agricultural and tenurial landscape in the wake of the Black Death.