With the Battle of Lewes, de Montfort had won control of royal government, but after the defection of several close allies and the escape from captivity of Prince Edward, he found himself on the defensive.

Simon de Montfort, 6th Earl of Leicester, had gained a dominant position in the government of the Kingdom of England after his victory at the Battle of Lewes a year earlier.

[6] With the Lords of the Welsh Marches now in rebellion, de Montfort solicited the aid of Llywelyn ap Gruffudd, the Prince of Wales.

Eventually Simon the Younger reached the baronial stronghold of Kenilworth, but Edward managed to inflict great losses on his forces, many of whom were quartered outside the castle walls.

[13] At Lewes, the baronial forces had gained confidence to win the day by a sense of divine destiny, reinforced by white crosses on their uniforms.

[17] De Montfort, facing such unfavourable numbers, decided to concentrate his forces on the centre of the enemy's front, hoping to drive a wedge through the line.

[16] In what has been referred to as "an episode of noble bloodletting unprecedented since the Conquest", de Montfort's son Henry was killed first, then Simon himself lost his horse and died fighting.

By the end of October, the royalists drew up the so-called Dictum of Kenilworth, whereby rebels were allowed to buy back their land at prices dependent on their level of involvement in the rebellion.

[21] In regard to wide-scale confrontations, the Battle of Evesham and its aftermath proved decisive: it ended baronial opposition in the reign of Henry III.