LEICESTER, ENGLAND—In 1485, Richard III died on the field during the Battle of Bosworth, the last major battle of the War of the Roses, which pitted the Houses of Lancaster and York against one another in a bloody civil conflict. A defining moment in English history, the battle was long thought to have taken place at a site called Ambion Hill near the town of Leicester. But a team led by archaeologist Glen Foard has discovered that the fight actually took place two miles away, near a marsh now known as Fen Hole. Over the past several years, Foard's group used metal detectors to find numerous artifacts that helped them pinpoint the battlefield's location. Among the discoveries was a silver-gilt badge shaped like a boar, which was Richard III's emblem, and was probably worn by one of his knights.