Henry III, King John's son, was only nine when he became King. By 1227, when he assumed power from his regent, order had been restored, based on his acceptance of Magna Carta. However, the King's failed campaigns in France (1230 and 1242), his choice of friends and advisers, together with the cost of his scheme to make one of his younger sons King of Sicily and help the Pope against the Holy Roman Emperor, led to further disputes with the barons and united opposition in Church and State. Although Henry was extravagant and his tax demands were resented, the King's accounts show a list of many charitable donations and payments for building works (including the rebuilding of Westminster Abbey which began in 1245).
The Provisions of Oxford (1258) and the Provisions of Westminster (1259) were attempts by the nobles to define common law in the spirit of Magna Carta, control appointments and set up an aristocratic council. Henry tried to defeat them by obtaining papal absolution from his oaths, and enlisting King Louis XI's help. Henry renounced the Provisions in 1262 and war broke out. The barons, under their leader, Simon de Montfort, were initially successful and even captured Henry. However, Henry escaped, joined forces with the lords of the Marches (on the Welsh border), and Henry finally defeated and killed de Montfort at the Battle of Evesham in 1265. Royal authority was restored by the Statute of Marlborough (1267), in which the King also promised to uphold Magna Carta and some of the Provisions of Westminster.