• Artist Sir William Allan's portrayal of the Battle of Prestonpans. Picture: Complimentary
The 1745 Battle of Prestonpans actually happened in a field 550 yards east of the spot where it has traditionally been sited.
Experts at Glasgow University made the discovery after finding few artefacts at the traditional location.
Dr Tony Pollard, of Glasgow University, one of the world's leading battlefield archaeologists, said: "We were not finding very much at the site or the materials you'd expect to discover.
"So we were thinking, 'Have we missed the stuff or has it been taken away?' But when the metal detectors went further east, we knew we had it." It appears previous records relating to the battle site have always been wrong.
Dr Pollard added: "Although this was a very well-documented battle with lots of eyewitness accounts, it was also very brutal and over quite quickly.
"It now seems that, in the excitement, some of the witnesses got it wrong."
The surprise victory at Prestonpans allowed Charles Stuart and the Jacobites to take the upper hand.
Dr Pollard is part of Glasgow University Archaeological Research Division (Guard), which is under threat from budget cuts.
His team was asked to investigate the site by the Battle of Prestonpans Heritage Trust two years ago. The study, which was funded by the Heritage Lottery Fund, revealed the main area of attack took place further towards Port Seton, and not on land south of Cockenzie Power Station.
More than 5,000 men were involved in the battle, which saw 300 killed and 1,000 soldiers captured by the Jacobites.
Archaeologists, helped by volunteers with metal detectors, unearthed piles of pistol balls, grapeshot and musket balls at the new site in fields owned by farmer Alistair Robertson. He said: "It is exciting to think it was across our fields that the famous Highland charge took place, and here that the main part of the battle was fought."
Dr Pollard and his group believe other fighting did take place on what was identified as the battle site originally, but not the historic charge.
There are now plans to display the findings in a visitor centre in the area, which already has a memorial cairn to the dead.
Dr Gordon Prestoungrange, chairman of the battle trust, said: "This battle was one of the most important in Scottish history and has the potential to draw many thousands of visitors to this part of East Lothian.
"We want to safeguard it for the nation and provide interpretation to inform and educate.
"Now we have a definite idea of where the battle actually took place, we can be confident that we will be telling the story as it actually was."
Last week, lecturers at Glasgow University protested against proposed cuts, including at Guard, which would see 30 jobs lost at the division.
Academics from Guard have been involved in TV shows such as Channel 4's Time Team and BBC2's Two Men in a Trench.
The department was also involved in an archeological assessment of the impact of the M74 extension and advised the National Trust for Scotland on the setting up of a new visitor centre at the Culloden battlefield.
The division has now been given a temporary reprieve after the ruling court of Glasgow University set up a committee to look at its finances.
University officials had argued the unit was not viable because it was not meeting targets set for all departments to generate income.
However, a spokesman said: "The university court has established a committee to review Guard's activities and finances and will report back at the next meeting on 23 June."