How did Edward I become involved in the Barons' War?

Edward I’s involvement in the Barons' War was characterized by shifting loyalties and active military leadership during the conflict between his father, Henry III, and a baronial faction led by Simon de Montfort.

Initially, Edward was influenced by Montfort, his uncle by marriage, and even supported the baronial cause during the political crises of 1258–1260. However, he eventually broke with the extremists and returned to his father’s side. When civil war erupted in 1263, Edward fought for the royalist cause, though his aggressive behavior and conflicts with the citizens of London often hindered the king's efforts.

At the Battle of Lewes in 1264, Edward’s impulsive pursuit of the Londoners contributed to the royalist defeat, resulting in his capture. After escaping captivity in 1265, he took command of the royalist forces, successfully trapping and killing Montfort at the Battle of Evesham. Following this victory, Edward exerted significant control over the government, eventually helping to facilitate a settlement through the Dictum of Kenilworth.12