William of Ypres to the English throne following Henry I's death in 1135 finally changed William's fortunes for the better. He commanded Stephen's troops against the forces of their cousin, Henry's daughter Empress Matilda, who claimed the throne. Many of the soldiers were William's fellow Flemings, including his brother. Stephen's campaign in Normandy failed because the local noblemen refused to co-operate with William and other Flemings. William was much more active in England, where he took part in the Battle of Lincoln (1141), during which Stephen was captured by the Empress's forces. William led his contingent away when it became clear that the
Henry I of England gave birth to a sequence of two sons, Henry and Geoffrey, in 1133 and 1134. Relations between Henry, Matilda, and Geoffrey became increasingly strained during the King's final years. Matilda and Geoffrey suspected that they lacked genuine support in England. In 1135 they urged Henry to hand over the royal castles in Normandy to Matilda whilst he was still alive, and insisted that the Norman nobility swear immediate allegiance to her, thereby giving the couple a more powerful position after Henry's death. Henry angrily declined to do so, probably out of concern that Geoffrey would try to seize power in