The tiny island of St Helena, 1,000 miles off the coast of south-west Africa, acted as the landing place for many of the slaves, captured by the Royal Navy during the suppression of the slave trade between 1840 and 1872. During this period a total of around 26,000 freed slaves were brought to the island, most of whom were landed at a depot in Rupert's Bay. The appalling conditions aboard the slave ships meant that many did not survive their journey, whilst Rupert's Valley  arid, shadeless, and always windy  was poorly suited to act as a hospital and refugee camp for such large numbers. At least 5,000 people are likely to have been buried there.

Part of the cemetery was investigated between 2006 and 2008 in advance of a new road that had to pass through Rupert's Valley to provide access to the proposed airport project. Some 325 bodies in a combination of individual, multiple and mass graves were discovered. Only five individuals were buried in coffins: one adolescent and four still- or newborn babies. The remainder had been placed (or thrown) directly into shallow graves, before being hastily covered. In some cases mothers were buried with their presumed children, or sometimes the bodies were so close that there might have been a familial relationship.

Now archaeologists, led by Dr Andrew Pearson of the Department of Archaeology and Anthropology at the University of Bristol, are publishing for the first time the results of their discoveries and the subsequent scientific investigations of the human remains and associated grave goods buried with them.

Osteological analysis shows that 83 per cent of the bodies were those of children, teenagers or young adults  prime material for the slave traders who sought victims with a long potential working life. In most cases the actual cause of death is not clear, but this is unsurprising because the main killers aboard a slave ship (such as dehydration, dysentery and smallpox) leave no pathological trace. Nevertheless, scurvy was widespread on the skeletons; several showed indications of violence and two older children appear to have been shot.

Despite its horrific nature, the archaeology showed those buried within the graveyard as more than simply victims. These were people from a rich culture, with a strong sense of ethnic and personal identity. This is best evidenced by numerous examples of dental modifications, achieved by chipping or carving of the front teeth. A few had also managed to retain items of jewellery (beads and bracelets), despite the physical 'stripping process' that would have taken place after their capture, prior to embarkation on the slave ships.

In addition to the large number of beads, burial conditions allowed for the survival of textiles, including ribbons. A number of metal tags were also found on the bodies that would have identified the slaves by name or number.

Dr Andrew Pearson, director of the project, commented: "Studies of slavery usually deal with unimaginable numbers, work on an impersonal level, and, in so doing, overlook the individual victims. In Rupert's Valley, however, the archaeology brings us (quite literally) face-to-face with the human consequences of the slave trade."

Professor Mark Horton said: "Here we have the victims of the Middle Passage  one of the greatest crimes against humanity  not just as numbers, but as human beings. These remains are certainly some of the most moving that I have ever seen in my archaeological career."

The artefacts from the excavations are currently at the University of Bristol and will be transferred to Liverpool for an exhibition at the International Slavery Museum in 2013 before returning to St Helena. The human remains will shortly be re-interred on St Helena.