The English Civil War Battle of Naseby was fought on June 14, 1645. It was a decisive battle in the English Civil War, with the Parliamentarian forces led by Oliver Cromwell defeating the Royalist forces of King Charles I. The battle was fought near the village of Naseby in Northamptonshire and resulted in a major victory for the Parliamentarians. This victory marked a turning point in the war, leading to the eventual defeat of the Royalists and the establishment of the Commonwealth of England.