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. Events= February 10 - Mongols overrun Baghdad, burning it to the ground and killing 800,000 citizens Llywelyn the Last declares himself Prince of Wales. ... Simon de Montfort, 6th Earl of Leicester (1208 – August 4, 1265) was the principal leader of the baronial opposition to king Henry III of England. ... Henry III (October 1, 1207 – November 16, 1272) is one of the least-known British monarchs, considering the great length of his reign. ...

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 Gallicisation which had taken place in the decades immediately before (see entry on Henry III of England). Sheriff is both a political and a legal office held under English common law, Scots law or American common law, or the person who holds such office. ... Henry III (October 1, 1207 – November 16, 1272) is one of the least-known British monarchs, considering the great length of his reign. ...

The Provisions of Oxford were replaced next year in 1259 by the Provisions of Westminster. For broader historical context, see 1250s and 13th century. ...

These Provisions were overthrown by Henry, with papal sanction, in 1261, which seeded the start of the Second Barons' War (1263-67), which the King won. Events July 25 - Constantinople re-captured by Nicaean forces under the command of Michael VIII Palaeologus, Byzantine Empire re-formed August 29 - Urban IV becomes Pope, the last man to do so without being a Cardinal first Bela IV of Hungary repels Tatar invasion Charles of Anjou given rule of... The Second Barons War (1264–1267) was a civil war in England between the forces of a number of rebellious barons lead by Simon de Montfort, against the Royalist forces led by Prince Edward (later Edward I of England). ...