1240s in England

Monarch – Henry III

• 1240
  • Dafydd ap Llywelyn, Prince of Wales, pays homage to King Henry III and agrees to arbitration over the right to rule Wales.[1]
  • Old St Paul's Cathedral in London is consecrated.
  • First perambulation of Dartmoor.[2][3]
• 1241
  • 1 February – Boniface of Savoy, the Queen's uncle, is enthroned as Archbishop of Canterbury.
  • 10 August – Eleanor, Fair Maid of Brittany dies captive at Bristol, ending the senior line of Geoffrey II, Duke of Brittany.
  • October – After defeat in a military campaign, Dafydd ap Llywelyn makes Henry his heir.[1]
• 1242
  • May – English army supports rebels in Poitou against French rule.[1]
  • Royal troops seize the island of Lundy, occupied by the fugitive William de Marisco.
• 1243
  • September – England signs a truce with France.[1]
• 1244
  • Dafydd ap Llywelyn forms alliance of minor Welsh rulers in Wales and begins revolt against English rule.
  • August – Henry blockades Scotland and musters an army at Newcastle upon Tyne after Scots threaten the border.[1]
  • November – Bishops and barons refuse to pay taxes demanded by King Henry, and insist on administrative reforms.[4]
• 1245
  • English army campaigns in north Wales to subdue Dafydd ap Llywelyn. A truce is agreed in the autumn, and Henry returns to England.[1]
  • The rebuilding of Westminster Abbey in Gothic style begins.[4]
• 1246
  • Cistercians, together with the King's brother, Richard, 1st Earl of Cornwall, found Hailes Abbey in Gloucestershire.[1]
  • Dafydd ap Llywelyn, who had lately claimed the title of prince of Wales, dies and the resistance of the Welsh against English forces in Wales collapses.
• 1247
  • April – Treaty of Woodstock: Dafydd ap Llywelyn's successors, the Welsh princes Llywelyn ap Gruffudd and Owain ap Gruffudd acknowledge Henry as their overlord.[1]
  • 13 June – Coinage reform introduces a new silver coin and establishes seventeen local mints.[1]
  • Romford established as a market town.[5]
  • The Bethlem Royal Hospital founded in London.[6]
• 1248
  • 11 March – Richard of Cornwall presides at the first Trial of the Pyx to determine the purity of coinage.[1]
  • Simon de Montfort, 6th Earl of Leicester appointed as governor of Gascony, but soon proves unpopular.[1]
• 1249
  • Spring – Bequest of William of Durham for the support of scholars in the University of Oxford, considered as the establishment of University College there.[4]

• 1240
  • 29 September – Margaret of England, daughter of Henry III of England and consort of Alexander III of Scotland (died 1275)
• 1241
  • Eleanor of Castile, queen of Edward I of England (died 1290)
• 1243
  • 2 September – Gilbert de Clare, 6th Earl of Hertford, politician (died 1295)
• 1245
  • 16 January – Edmund Crouchback, 1st Earl of Lancaster, son of Henry III of England (died 1296)
• 1246
  • 14 September – John FitzAlan, 7th Earl of Arundel (died 1272)
• 1247
  • Little Saint Hugh of Lincoln (died 1255)
• 1249
  • Humphrey de Bohun, 3rd Earl of Hereford (died 1297)

• 1240
  • Edmund Rich, Archbishop of Canterbury (born 1175)
  • William de Warenne, 5th Earl of Surrey (born 1166)
• 1241
  • 10 August – Eleanor, Fair Maid of Brittany, daughter of Geoffrey II, Duke of Brittany (born 1184)
  • 1 December – Isabella of England, princess (born 1214)
• 1242
  • 26 March – William de Forz, 3rd Earl of Albemarle (year of birth unknown)
• 1243
  • 12 May – Hubert de Burgh, 1st Earl of Kent (born c. 1165)
• 1245
  • c. June – Elias of Dereham, canon and building designer
  • 21 August – Alexander of Hales, theologian
• 1246
  • 31 May – Isabella of Angoulême, queen of John of England (born c. 1187)
  • Thomas De Melsonby, last hermit of the Farne Islands[7]
  • Richard Fitz Roy, illegitimate son of King John (born c. 1190)
• 1247
  • William de Ferrers, 4th Earl of Derby (born c. 1168)