In 1258 a group of barons, led by Simon de Montfort, 6th Earl of Leicester, forced King Henry III of England to accept a new form of government in which power was placed in the hands of a council of 15 members who were to supervise ministerial appointments, local administration and the custody of royal castles. Parliament, meanwhile, which was to meet three times a year, would monitor the performance of this council.

A written confirmation of the agreement was sent to the sheriffs of all the counties of England in Latin, French and, significantly, in English. The use of the English language was symbolic of the Anglicisation of the government of England and an antedote to the Frenchification which had taken place in the decades immediately before (see entry on Henry III of England).

The Provisions of Oxford were replaced next year in 1259 by the Provisions of Westminster .

These Provisions were overthrown by Henry, with papal sanction, in 1261, which seeded the start of the Barons' War (1263-67), which the King won.