Researchers from Sheffield University have found that Greensted church near Chipping Ongar was built in the late 11th century. The nave was erected using oak trunks, split in half and sunk in the ground. Dendrochronology - a technique that dates wood by examining the sequence of rings - has established that the trees were cut down circa 1070, when they were about 200 years old.
The discovery has challenged theories as to the origins of the church and why it survived - it is the only wooden stave structure still standing in Britain. It had long been believed that St Edmund, a Saxon king killed by the Danes in about 870, had lain briefly in state in the church. As a result, it was said, Greensted became a place of pilgrimage.
The dendrochronological evidence threatens the St Edmund theory, although there are signs of an earlier chapel. The Rev Tom Gardiner, rector of Greensted, said: "This place is still very much a mystery."
The latest hypothesis is that the church originally belonged to the local lord of the manor, who had a second estate and church which was modernised, while Greensted was largely forgotten. The church is now in need of renovation, and Mr Gardiner has appealed for pounds 10,000 to fund essential repairs.
The good news for Green-sted church is that it is still the oldest wooden building in Europe. Ian Tyers, a dendrochronologist at Sheffield University who dated the Greensted oaks, has checked rival constructions in Scandanavia, and found none dates from before the early 13th century.Reuse content