The Battle of Bosworth did not happen at the spot visited by thousands each year, new research suggests.
Henry Tudor defeated Richard III in the battle in 1485, ending the 30-year War of the Roses. Several sites have been proposed for the battlefield, in which at least 1,000 people lost their lives.
The most popular view has been that it was fought on Ambion Hill, near the town of Market Bosworth, in Leicestershire, where there is a visitor centre and tourist trail. There is another theory that it took place in Atherstone, Warwickshire.
But according to BBC programme Inside Out, it is certain that neither of these sites are the correct place.
The Battlefields Trust took oil soil samples, used metal detectors and trawled through historic documents to carry out its research.
A BBC spokesman said it was not yet releasing details of where it thought the actual site of the battle was.