Bronze barrel fragments and very early lead shot were unearthed by a metal detectorist at the site of the 1461 battle of Towton in Yorkshire.
The clash between Lancastrian king Henry VI and England’s first Yorkist king, Edward IV, during the Wars of the Roses, has gone down in history as one of the bloodiest ever fought.
The fragments belonged to two crudely cast, pole-supported guns which exploded because of the cold as the battle raged in a snowstorm, lab tests confirmed.
The discovery of a lead ball with an iron core was also highly significant because it is the earliest composite lead bullet known in Europe.
Archaeologist Tim Sutherland, who has been working on the site since 1996, said it was an exciting discovery that marked the start of modern warfare.
‘There are no parallels for any such finds, on certainly a British medieval battlefield but probably a European one as well,’ he added.
University of York lecturer Mr Sutherland may yet rewrite the battle’s history as the site yields more of its secrets.
The ten-hour clash is thought to have killed 28,000 men but Mr Sutherland believes the figure is closer to 4,000.
However, he agrees it changed the course of English history. ‘Everybody has heard of King Richard III and if it hadn’t been for Towton… he would not have taken the throne,’ he said.