It was believed the battle took place west of Donnington, north of Stow
A monument marking an official battle site in the Cotswolds might be in the wrong place, historians have claimed.
The memorial to the Stow-on-the Wold battle stands about three miles (4.8km) north-west of the town, on a hill outside Donnington.
The Royalist defeat at Stow, in March 1646, was the last major battle of the first English Civil War.
But the local civic society said new investigations suggest the site was two miles closer to Stow itself.
Spokesman Tim Norris said the Cavaliers fled the site of battle and the infantry was chased back to Stow square by the Roundheads.
"[The Royalists] must have been much nearer to Stow in order for the infantry to get into the square before the parliamentary cavalry would have overtaken them," he said.
"You can imagine an infantry man loaded up with all his kit and his musket would have a job to run. He must have been very tired on march to have escaped men on horses at that sort of distance."
Doubt was cast when the society started to investigate how to improve access for visitors to the battlefield.
The siting of the monument in 2002 was based on the discovery of some lead shot and also local folklore.
The Battlefields Trust is applying for a £50,000 lottery grant to carry out excavations at a new site closer to Stow.