Ancient DNA confirms Late Roman ‘family’ grave at Cheddington, Bucks

Long-suspected familial relationships within a shared grave of Late Roman date at Cheddington, Buckinghamshire, have now been confirmed by ancient DNA (aDNA) analysis.

The grave was just one of many features excavated in 2018 by Cotswold Archaeology at this multiperiod site, the later history of which featured in one of our 2021 Christmas videos . Further details of the site are available online (Report no. MK0123_1), and a summary was published earlier this year in Records of Buckinghamshire . As a small piece of additional research, the aDNA from all three individuals within the grave were sequenced as part of the Thousand Ancient Genomes from Great Britain research project undertaken by the Ancient Genomics Laboratory at the Francis Crick Institute in London.

The shared grave under excavation
The shared grave under excavation

The grave was one of a pair found in the western corner of the excavation, lying 3m apart. It contained the skeletal remains of two adult females and a preterm baby (foetus). These had been interred together into the grave, with the baby located on or in the abdominal area of one female, i.e. potentially still in utero. This female was estimated to have been approximately 25-29 years at the time of death; the other was older, at over 45 years. The preterm baby was approximately 32-36 weeks gestation: 37+ weeks is considered full term. It was not clear whether it had died in utero, or had been born and then died and placed in that location.

A double (or triple) burial such as this is intriguing and, with no dating evidence found in the grave, samples were taken from both adult skeletons for radiocarbon dating. The results of this placed the burials somewhere in the late Roman period, between the mid 3rd century and early 5th century AD (255-535 cal. AD and 251-433 cal. AD).

The shared grave, as excavated
The shared grave, as excavated

Most inhumation burials from the late Roman period are of single individuals but, where this is not the case (e.g. as at another CA site in Gloucester), it may be that those in the grave were related to one another. Most commonly, double graves are of an adult (presumably a parent) and a child, so to have two adults and a foetus is unusual. Samples from all three skeletons were sent for aDNA analysis in the hope that it would help us understand the relationships between these individuals.

The shared grave under excavation
The shared grave under excavation, overhead photograph

The results of the aDNA analysis confirmed that both adult skeletons were female, and that the foetus was male (something which could not be determined osteologically). The mitochondrial DNA from the younger female and the foetus confirmed they were mother and son. More remarkably, the older female was unrelated to the younger female but was a second-degree relative of the foetus, most likely its paternal grandmother (or alternatively, a paternal aunt).

The aDNA results confirm that the people buried together in this grave were related, and potentially  were three generations of the same family who had died within a short space of time to one another. It is entirely possible that the adults were related by marriage and mother died in the late stages of pregnancy. A fascinating and poignant burial, which gives us a small window into family relationships in the past.

Sharon Clough

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