Which 1264 battle ended with Simon de Montfort capturing King Henry III of England?

The 1264 battle that ended with Simon de Montfort capturing King Henry III of England was the Battle of Lewes.

The battle took place on 14 May 1264 during the Second Barons’ War, an English civil conflict over royal government and the king’s relationship with the barons. Simon de Montfort, Earl of Leicester, led the reforming baronial forces against Henry III and the king’s son, Edward, later Edward I.

Montfort’s army defeated the royal forces near Lewes in Sussex. Henry III was captured, and Prince Edward was compelled to accept the Mise of Lewes, an agreement that temporarily strengthened baronial influence over government. The settlement did not end the conflict permanently.

Edward escaped captivity in 1265 and defeated Montfort at the Battle of Evesham later that year. That victory restored royal authority and ended the baronial regime. The Battle of Lewes is therefore important both as a knightly military confrontation and as a constitutional crisis in medieval England.