1140s in England

Monarch – Stephen (to 8 April 1141), Matilda (to 1 November 1141), Stephen

• 1140
  • December – The Anarchy: Earl Ranulf of Chester captures Lincoln.[1]
  • Dryburgh Abbey founded.[1]
• 1141
  • 2 February – The Anarchy: At the First Battle of Lincoln, Robert, 1st Earl of Gloucester and Empress Matilda wrest control of the throne from King Stephen, who is captured and imprisoned.[1]
  • 8 April – The Anarchy: Matilda is proclaimed "Lady of the English".[1]
  • 24 June – The Anarchy: Matilda is forced to flee Westminster during a royal banquet, and flees to Oxford.[1]
  • July – The Anarchy: Matilda I of Boulogne, wife of Stephen, recaptures London.[1]
  • 14 September – The Anarchy: Rout of Winchester: Robert of Gloucester captured by forces loyal to Stephen during fighting at Winchester.[1]
  • 1 November – The Anarchy: Stephen and Robert exchanged as prisoners ending the reign of Matilda.[1]
• 1142
  • Matilda grants the church of Oakley, Buckinghamshire, with its chapels of Brill, Boarstall and Addingrove, to the monks of the Priory of St Frideswide, Oxford.
  • Matilda's son Henry comes to England for the first time.[1]
  • 26 September – The Anarchy: Stephen captures Oxford, and besieges Matilda inside the castle.[1]
  • December – The Anarchy: Matilda escapes from Oxford Castle across the snow in a white cape for camouflage, according to Henry of Huntingdon.[2]
• 1143
  • 1 July – The Anarchy: Battle of Wilton – Robert, 1st Earl of Gloucester, defeats Stephen at Wilton.
  • The Anarchy: Geoffrey de Mandeville, a supporter of Matilda, is deprived of his castles in Essex, but subsequently captures Ely and campaigns in Cambridgeshire.[1]
  • Robert of Ketton makes the first European translation of the Qur'an into Latin.[3]
• 1144
  • 11 February – Robert of Chester completes the translation of Book of the Composition of Alchemy from Arabic to Latin. It is the first book in Europe to describe alchemy.[4]
  • 22 March – A young apprentice, William of Norwich, is murdered, a crime attributed to the Jews by the Norwich mob, the first known medieval accusation of blood libel against Jews.
  • 28 November–24 December – the Siege of Edessa by Muslims led by Imad ad-Din Zengi eliminates the Crusader principality of Outremer, the news causing the pope to preach a new Crusade.
  • Matilda's husband Geoffrey V of Anjou, completes the conquest of Normandy.[1]
• 1145
  • The Anarchy: Stephen captures Faringdon Castle.[1]
  • Woburn Abbey founded.[5]
  • Robert of Chester makes the first translation of an algebra text from Arabic into Latin.[1]
• 1146
  • The Anarchy: Ranulf of Chester is captured, but released after surrendering his castles.[1]
  • Many knights and barons leave England to take part in the Second Crusade.[1]
• 1147
  • The Anarchy: Henry arrives in England to fight for Matilda, but is defeated in skirmishes, and returns to Normandy.[1]
  • The Anarchy: Ranulf of Chester lays waste to the land around Coventry, but fails to capture the city itself.[1]
  • 24 October – English crusaders capture Lisbon from the Moors.[1]
• 1148
  • February – The Anarchy: Empress Matilda forced to return to Normandy.[1]
• 1149
  • 22 May – King David I of Scotland knights Henry, and cedes northern Lancashire to Ranulf of Chester, in return for control of Carlisle.[1]
  • King David I of Scotland attempts to wrest control of the Bishopric of Durham and the Archbishopric of York from Stephen, but fails.

• 1140
  • William FitzRalph, future Sheriff of Nottingham and seneschal of Normandy
• 1146
  • William Marshal, 1st Earl of Pembroke, soldier and statesman (died 1219)
• 1147
  • Hugh de Kevelioc, 3rd Earl of Chester (died 1181)

• 1140
  • 6 February – Thurstan, Archbishop of York (born c. 1070 in Normandy)
• 1141
  • Aubrey de Vere, Lord Great Chamberlain (born 1062)
• 1142
  • Orderic Vitalis, chronicler (born 1075)
• 1143
  • William of Malmesbury, historian (born 1080)
• 1144
  • Geoffrey de Mandeville, 1st Earl of Essex
• 1147
  • 31 October – Robert, 1st Earl of Gloucester, politician (born c. 1090)
• 1148
  • 3 January – Anselm of St Saba, abbot of Bury St Edmunds (born 1136 in Italy)
  • 6 January – William de Warenne, 3rd Earl of Surrey (born 1119; killed on crusade)
  • 30 January (approximate date) – Serlo (abbot of Cirencester)
  • Gilbert de Clare, 1st Earl of Pembroke (born c. 1100)