Louis IX's ruling in favor of Henry III at Amiens directly triggered the Second Barons' War and reshaped English constitutional conflict.
Key Facts
- Date of settlement
- 23 January 1264
- Arbitrator
- King Louis IX of France
- Ruling favored
- King Henry III of England
- Baronial leader opposed
- Simon de Montfort
- Conflict triggered
- Second Barons' War
- Final rebel surrender
- Kenilworth Castle, end of 1266
Location
Cause → Event → Consequence
Discontent among English barons over foreign influence at court and Henry III's heavy taxation led to the Provisions of Oxford in 1258, placing royal government under a baronial council. Repeated revocations and reinstatements of those Provisions brought England to the brink of civil war by 1263, prompting both sides to seek arbitration.
In January 1264 at Amiens, King Louis IX of France issued his arbitration ruling, known as the Mise of Amiens. A firm believer in royal prerogative, Louis ruled entirely in Henry III's favor, annulling the Provisions of Oxford and restoring full royal authority, a decision the rebellious barons found wholly unacceptable.
The barons rejected the settlement and war broke out almost immediately. Simon de Montfort defeated Henry at the Battle of Lewes in May 1264, temporarily seizing control of government. Prince Edward later defeated and killed Montfort at Evesham in August 1265. Remaining rebels surrendered by late 1266 and received pardons under the Dictum of Kenilworth.
Political Outcome
Louis IX ruled entirely in favor of Henry III, annulling the Provisions of Oxford and restoring full royal prerogative; the barons rejected the ruling and resumed hostilities.
Royal authority constrained by the Provisions of Oxford under a baronial council
Full royal prerogative nominally restored by arbitration, though immediately contested by baronial war