A discovery of 36 decapitated bodies has left York archaeologists baffled.
The skeletons were found near the Roman road from York to Tadcaster
York Archaeological Trust (YAT) found the skeletons of 49 young men and seven children at a Roman cemetery in The Mount area of the city.
Most of the men had had their heads cut off while another had been bound with iron shackles.
Patrick Ottaway from YAT said the Romans had no tradition of killing people by beheading them and the heads may have been taken from dead bodies.
"One theory we are working on is that the men's heads were removed after death with a very sharp implement through the cervical vertebrae," Dr Ottaway explained.
"After removal their skulls had been placed in the grave by their feet, legs or pelvis as part of a burial ritual.
"Romans also believed that the head was the seat of the soul and they may have cut off their heads to stop them haunting the living."
The most puzzling discovery was the man found shackled with two iron rings around his feet.
"We haven't seen anything like this before in Britain," Dr Ottaway continued.
"The shackles may have been put on as a punishment or to stop the dead escaping.
"York has quite a reputation for ghosts and Romans were terrified of them and their influence."