Stephen, King of England recognised Stephen's son Eustace as Duke of Normandy in exchange for Eustace giving fealty to the French king. Stephen was less successful, however, in regaining the Argentan province along the Normandy and Anjou border, which Geoffrey had taken at the end of 1135. Stephen formed an army to retake it, but the frictions between his Flemish mercenary forces led by William of Ypres and the local Norman barons resulted in a battle between the two halves of his army. The Norman forces then deserted the King, forcing Stephen to give up his campaign. Stephen agreed to another truce with Geoffrey,
History of England 28 September 1066, William of Normandy invaded England in a campaign called the Norman Conquest. After marching from Yorkshire, Harold's exhausted army was defeated and Harold was killed at the Battle of Hastings on 14 October. Further opposition to William in support of Edgar the Ætheling soon collapsed, and William was crowned king on Christmas Day 1066. For five years, he faced a series of rebellions in various parts of England and a half-hearted Danish invasion, but he subdued them and established an enduring regime. The Norman Conquest led to a profound change in the history of the English state.