A MACABRE mystery from York's ancient past has been uncovered in a city street.

Experts from York Archaeological Trust have unearthed an "extraordinary" Roman cemetery near The Mount.

They found 56 skeletons, of 49 young men and seven children - perhaps not unusual in itself, since the Roman route which ran approximately along the present Tadcaster Road was lined with cemeteries.

But most of these young men had been decapitated - and one of those was bound with shackles, a find believed to be the only one of its kind in the Roman world. Now the skeletons, and other remains like pottery found with them, have been taken to be cleaned and analysed by the trust.

Archaeologists are beginning the task of trying to understand why the heads were removed. Were they executed or killed in battle? Was the decapitation part of a burial ritual, perhaps aimed at ensuring the dead did not return to haunt the living?

Patrick Ottaway, the trust's head of field work, said he believed the ritual theory was the more likely one, since the state of the bodies suggested the heads were removed after death.

He thought they dated from about 200AD, roughly the period that Emperor Septimius Severus came north to York with an army to fight in Scotland.

Dr Ottaway said one "line of inquiry" was to check whether the bodies could be those of members of that army. They would liaise with archaeologists abroad to see whether any burial rituals from the Rhineland, where many soldiers in Roman armies originated, or North Africa, where the emperor came from, fitted with this find.

Another intriguing find was that of a young child buried in a casket. It was unusual for children of that age to receive elaborate funerals, so this could be a much-loved child, or one from an important family.

But one of the strangest aspects of the find was the shackled body. "That really is odd. We've never had anything like that before, in Roman Britain or the Roman world," said Dr Ottaway.

The shackles consisted of thick iron rings, raising the question of whether this could also be a means of ensuring the dead stayed where they were.

Pupils from the nearby Mount School are in the process of setting up a website about the find, which was on a small plot of land at Driffield Terrace. The site will be used for schoolchildren from all over York.

Updated: 09:54 Thursday, February 24, 2005