4:17pm UK, Thursday November 25, 2004

A mysterious inscription on a stately home monument is likely to be a message from an 18th century Christian sect - not the location of the Holy Grail.

That is the view of legendary World War Two code-breakers from Bletchley Park in Buckinghamshire.

180 grail codebreakers lawn monument 11/5/04

Codeworkers at work

The significance of the sequence of letters on the Shepherd's Monument at the Shugborough Estate in Staffordshire has baffled visitors for years.

The marble tablet, commissioned in 1748, features a carved image of a Nicolas Poussin painting with the letters D.O.U.O.S.V.A.V.V.M. underneath.

After months of study, the Bletchley Park sleuths say it is likely to stand for "Jesus (As Deity) Defy", a message from a sect called the Priory of Sion.

The order had to keep its views secret because the Church of England, which viewed Jesus as an earthly prophet, thought they were heretical.

It had been rumoured the riddle would reveal the location of the Holy Grail.

According to myth, the Grail was used either by Jesus at the Last Supper or by Mary Magdalene to catch Jesus' blood during the Crucifixion.

The quest for the Grail became a popular theme in art, and in more recent times was parodied by the Monty Python team in their classic film.