De Montfort also supports the 1259 Provisions…

De Montfort also supports the 1259 Provisions of Westminster, which further strengthen the baronial position by endowing the newly created baronial council with substantial governmental powers.

After Henry grudgingly assents to these reforms, a split develops among the magnates—between radicals, led by Simon de Montfort, and conservatives.

The king’s son and heir Edward, displaying masterfulness in the disputes with the conservative barons, supports Simon’s faction, but will later change sides.