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,
Anglo-Norman language Anglo-Norman, but that usage is derived from the French name for the islands: "îles anglo-normandes". The variety of French spoken in the islands is Norman and not the Anglo-Norman of medieval England. Anglo-Norman was never the main administrative language of England: Latin was the major language of record in legal and other official documents for most of the medieval period. However, from the late 12th century to the early 15th century, Anglo-Norman French and Anglo-French were much used in law reports, charters, ordinances, official correspondence, and trade at all levels; they were the language of the King, his court and