The history of Harleston will have to be rewritten following a hi-tech tree ring dating survey which has thrown up results that have left townsfolk stunned.

The history of Harleston will have to be rewritten following a hi-tech tree ring dating survey which has thrown up results that have left townsfolk stunned.

The Harleston and District Historical Society commissioned a Sheffield-based dendrochronologist to tree ring date some of the town's oldest buildings.

Next Thursday, Ian Tyers will reveal the results of the survey - and highlight an important discovery in the history of timber-framed buildings.

Among the findings, he will

show how dendrochronology has revealed that Orkney Cottage, sitting in the middle of the old market plain and believed built in the late 19th century, actually dates back to the spring of 1769.

Susan Brown, of the Norfolk Historic Buildings Group, said: "A building doesn't have to be the oldest for a record to be valuable. This intriguingly-late date for quality building in oak is a new benchmark in the history of buildings in Norfolk.

"It shows that this type of construction was being used later than we thought."

Another discovery is that the town's oldest building, a private house in Old Market Place, is made of elm and not oak as had been thought, meaning it cannot be dated.

Ian Carstairs, of the historical society, said: "Its timbers were so blackened that the type of wood from which it was made was obscured. The discovery, along with the unexpected use of elm in a number of other key buildings, raises new questions as to why it was favoured at the time of their construction and what was happening in the countryside around."

The Lottery-funded project, commissioned by the historical society's heritage group, aims to guide their future work to

unravel the origins of the town's commercial centre.

Margaret Griffiths, from the heritage group, said: "Once, the area between Broad Street and The Thoroughfare was a market plain. In time, the traders' booths were replaced by buildings. But when and how this happened is unclear."

Mr Tyers' talk will explain how tree ring dating works and the way in which the pilot project can be used as a springboard to future historic research. It takes place at the Swan Hotel, The Thoroughfare, Harleston, on Thursday, March 15 at 7.30pm, admission free.