John Giffard left him because he refused to allow him to exact ransom from a prisoner, contrary to the agreement made after Lewes.

A greater danger opened when the young Earl of Gloucester, though enriched with the estates of the foreigners, held himself aloof from the Justiciar, and resented Leicester's prohibition of a tournament, his naming the wardens of the royal castles by his own authority, his holding Edward's fortresses on the Welsh marches by his own garrisons.
[Sidenote: Edward and Gloucester] Gloucester's later conduct proves the wisdom of Leicester's precautions.

In the spring Parliament of 1265 he openly charged the Earl with violating the Mise of Lewes, with tyranny, and with aiming at the crown.

Before its close he withdrew to his own lands in the west and secretly allied himself with Roger Mortimer and the Marcher Barons.

Earl Simon soon followed him to the west, taking with him the king and Edward.