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,
Norman conquest of England the invasion, intermarriage between the native English and the Norman immigrants had become common. By the early 1160s, Ailred of Rievaulx was writing that intermarriage was common in all levels of society. The impact of the conquest on the lower levels of English society is difficult to assess. The major change was the elimination of slavery in England, which had disappeared by the middle of the 12th century. There were about 28,000 slaves listed in "Domesday Book" in 1086, fewer than had been enumerated for 1066. In some places, such as Essex, the decline in slaves was 20 per cent