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,
Kingdom of England Norman conquest of England, however, some Norman lords began to attack Wales. They conquered and ruled parts of it, acknowledging the overlordship of the Norman kings of England but with considerable local independence. Over many years these "Marcher Lords" conquered more and more of Wales, against considerable resistance led by various Welsh princes, who also often acknowledged the overlordship of the Norman kings of England. Edward I defeated Llywelyn ap Gruffudd, and so effectively conquered Wales, in 1282. He created the title Prince of Wales for his heir, the future Edward II, in 1301. Edward I's conquest was brutal and