They found the skeletal remains of fifty-one men, all decapitated before their bodies were thrown in a pit. Their heads were also found, stacked to one side.
At first, the bodies were believed to have been from people who lived in ancient or Roman times, but radio-carbon dating revealed that they were killed between 890 and 1034, when the South of England was pillaged by Viking raiders from Scandinavia.
What they found shook even experienced archaeologists used to dealing with the remains of the long dead. David Score, of Oxford Archaeology, the project manager, said: "When you are there surrounded by bones with a pile of skulls grimacing back at you, you can't help but imagine how they met their end. It would have been a scene of absolute horror."
Nothing else has been found in the grave so far. Mr Score said: "You might expect them to have been stripped of weapons and jewellery before execution, but the fact we haven't found so much as a bone toggle suggests they were naked when they were executed."
Angela Boyle, senior osteologist, said: "The overwhelming majority are aged from their late teens to about 25-years-old, with just a small number of older individuals. As a general group they are tall, robust in stature with good teeth and appear to have had healthy lifestyles.
"Most of the skulls exhibit evidence of multiple blows to the vertebrae, jawbones and skulls with a large, very sharp weapon such as a sword."
The identity of the skeletons may be revealed by their teeth. Isotopes in the enamel formed while the men were growing up will reveal whether their origins were in Scandinavia, Wessex — Alfred's kingdom — or northern England, where large numbers of Danes had settled.
David Score add, "The time period we’re now looking at is one of considerable conflict between the resident Saxon population and invading Danes. Viking raids were common and there were a series of major battles in the south of England as successive Saxon kings and Viking leaders fought for control.
"It is hoped that further radio carbon dating will be able to define the date range much more closely and other scientific techniques may be able to establish the origin of the individuals; were they Saxons or Vikings?”
The pit was discovered during road construction between Dorchester and Weymouth, venue for sailing events in the 2012 Olympics. A team of archaeologists had been following builders widening the A354 where it crosses the Ridgeway, a prehistoric track along the crest of the limestone hills of south Dorset.
