Waking the Birdoswald Dead
Analysing five funerary vessels from the Roman cemetery.
Roman funerary vessels feature at the newly opened Birdoswald Fort visitor centre on Hadrian’s Wall. They originate from the cemetery associated with the fort, situated at the top edge of the cliff overlooking the River Irthing. Rapid erosion threatened the site. To mitigate the loss of archaeology, the Historic England (HE) Excavation and Analysis team excavated part of the cemetery in 2009. This represents the only large-scale investigation of any military cemetery on Hadrian’s Wall and allowed us to explore cremation practice at the northern edge of the Roman Empire.
Investigating the vessels
The five vessels range in size and decoration. Four are cremation vessels in a type of black burnished ware and one is a Nene Valley ware beaker accompanying a cremation in a wooden box. They all date to the mid-late second century.
Analysis of the contents by our team of archaeological scientists has built our understanding of each individual and the practice of cremation
Four vessels broke into many pieces whist in the ground, with one losing its entire rim due to ploughing. The fifth vessel survived intact, protected by the stone-lined cist it lay in. All were block lifted and X-rayed prior to excavation under controlled conditions. Analysis of the contents by our team of archaeological scientists has built our understanding of each individual and the practice of cremation. This work has, in turn, informed the English Heritage displays in the new visitor centre.
Examination revealed information about the vessels’ treatment prior to burial. The largest had a hole repaired with lead.
The one intact vessel appears to have been ‘ritually killed’ before placing in the cist; a small hole had been deliberately cut out of the base. Evidence suggests that the four cremation vessels might have been placed near to the funeral pyre before the cremated remains were placed inside; warming, possibly by the pyre, has slightly eroded the surfaces and left soot on one.
X-radiography was a key tool for recording and examining the condition of the contents before micro-excavation. Surprisingly, for one vessel, the X-rays showed a collection of objects underneath the cremated remains. Once the bone was removed, it became apparent that the objects were fused together by iron corrosion. Unable to disentangle them, we turned to a variety of imaging tools to investigate what was present.
Computed radiography and micro-computed tomography (CT) scanning led to surprising results.
It appears that the base of the vessel had been lined with a piece of chain mail armour into which nine other objects had been placed.
The cremated bone was then placed on top. The presence of chain mail may commemorate a soldier but the amount is small and can only represent a portion of armour. This suggests a male, but dress accessories usually associated with a female are present: a bracelet or armlet, rings and beads and pendants. Part of a glass vessel rim was on top of the bracelet and may be from a vessel containing liquids used in the cremation ceremony.
One of the more challenging objects to identify was a large circular ring. A multidisciplinary approach was required to determine what it was made from.
It was not metal as it was nearly X-ray transparent and therefore barely visible in the images. Using portable X-Ray Fluorescence (XRF) the elements potassium, aluminium and silicon oxides were detected.
Crystalline grains resembling mica could be seen under microscopy suggesting a fine-grained sedimentary stone such as shale. This was confirmed using Fourier Transformed Infra-Red Attenuated Total Reflectance Spectroscopy (FTIR). The material and size suggests it is from a horse harness.
The human remains
Upon cremation, bones shatter into fragments, and in all five burials most fragments were less than 2 centimetres long. Furthermore, the burning process destroys or degrades the organic component precluding DNA and most stable isotope analyses. This severely limits the information that can be obtained, but by using a combination of tried and trusted techniques, and new methods, we were able to extract some useful data.
Each of the five vessels seemed to contain the remains of only one individual.
Four were adults (one male, one female, two of unknown sex) and one was a five-year old child. Each burial contained only about 10-35% of the amount of the bone one would expect from a whole skeleton. In part this may reflect losses due to disturbance or poor survival, but it seems inescapable that much less than the full amount was buried. This is not unusual for cremations in Roman Britain: similar quantities of bone were found in burials at nearby Brougham, Cumbria. In Roman times, it seems that it was not thought important to bury all the remains.
When subject to heat, bone undergoes a sequence of microstructural changes which can be detected by spectroscopic methods. We used FTIR to assess the intensity of firing of the bone to help elucidate the practice of cremation at Birdoswald. Results revealed a diversity of cremation practices. In three of the burials (the male and the two unsexed adults) there was a uniformly high intensity of burning, with prolonged exposure of remains to temperatures in excess of 600 degrees Centigrade. There was an evenness of firing of remains from front and back parts of the body, consistent with placement of corpses on top of the pyre.
The other two burials (the adult female and the child) showed more varied firing with some elements exposed to lower temperatures (about 300-500 degrees Centigrade). There was a tendency for the internal surfaces of bones to be less well fired than exterior surfaces, for example the inside surface of skull fragments were often less well fired than the outer surfaces. Because bones shatter into fragments during combustion, this pattern is consistent with a shorter duration of firing. In the adult female, upper parts of the body were also less well fired than the lower parts, suggesting insufficient fuel for uniform combustion or that the pyre may have been poorly managed.
The study of the objects and human remains from these vessels has been illuminating. Vessel SF33516 containing the collection of objects has revealed an unparalleled level of information. Micro-CT enabled us to both identify what is present and the process of deposition. More intriguing is that the human remains analysis and the objects suggest a female and that this burial was in close proximity to that of a child.
Further analysis of the soil from the vessels revealed charcoal fragments indicating hardwoods native to the British Isles were used on the pyre.
The human remains analysis provides new possibilities of unlocking information hidden within archaeological remains and enables us to describe past practices in new ways.
Working with our curatorial colleagues in the English Heritage Trust we reconstructed the vessels for display.
In the case of the vessel containing objects, we felt it was important for the public to see the contents as well as the external lattice work decoration. We used an ‘open book’ reconstruction allowing visitors to look inside and view the CT scans alongside the vessel.
The vessel with the lead repair was so distorted from the weight of the lead and soil that it was reconstructed in two halves and a special mount made.
Rob Collins (University of Newcastle) and Sophie Beckett (University of Cranfield) for their work on the vessel SF33516. Emily Carrol (University of Reading) for her FTIR work on the cremated bones. To our colleagues in the English Heritage Trust, Frances McIntosh and Leesa Vera –Stevens; and HE specialists working on this project.
About the authors
Karla Graham, ACR
Senior Archaeological Conservator at Historic England
Karla is an Icon Accredited Senior Archaeological Conservator for Historic England and an Accreditation Assessor for the Icon PACR scheme. She is leading on the revision of the HE Guidelines on the X-radiography of archaeological metalwork to include guidance on the use of computed radiography.
Simon Mays PhD
Human Skeletal Biologist for Historic England
As well as his role as Human Skeletal Biologist for Historic England, Simon is a Visiting Lecturer in the Department of Archaeology at the University of Southampton, and an Honorary Fellow in the School of History, Classics and Archaeology, University of Edinburgh. He has responsibility for developing and implementing policy regarding human skeletons excavated from archaeological sites.
Angela Middleton, MSc
Angela joined Historic England in 2007. She has a special interest in the conservation of waterlogged organic materials and has responsibility for providing advice, undertaking research and investigative conservation on material retrieved from land and marine sites.
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