to the ground, Alan fled to England and Berengar sought reconciliation. In 935, William married Luitgarde, daughter of Count Herbert II of Vermandois whose dowry gave him the lands of Longueville, Coudres and Illiers-l'Évêque. He also contracted a marriage between his sister Adela (Gerloc was her Norse name) and William, Count of Poitou, with the approval of Hugh the Great. In addition to supporting King Raoul, he was now a loyal ally of his father-in-law, Herbert II, both of whom his father Rollo had opposed. In January 936, King Raoul died and the 16-year-old Louis IV, who was living in exile in England, was persuaded by a promise of loyalty by William, to return and became king. The Bretons returned to recover the lands taken by the Normans, resulting in fighting in the expanded Norman lands. The new king was not capable of controlling his Barons and after William's brother-in-law, Herluin II, Count of Montreuil, was attacked by Flanders, William went to their assistance in 939, Arnulf I, Count of Flanders retaliated by attacking Normandy. Arnulf captured the castle of Montreuil-sur-Mer expelling Herluin. Herluin and William cooperated to retake the castle.David Nicholas, Medieval Flanders (London: Longman Group UK Limited, 1992), p. 40 William was excommunicated for his actions in attacking and destroying several estates belonging to Arnulf. William pledged his loyalty to King Louis IV when they met in 940 and, in return, he was confirmed in lands that had been given to his father, Rollo. In 941, a peace treaty was signed between the Bretons and Normans, brokered in Rouen by King Louis IV which limited the Norman expansion into Breton lands. The following year, on 17 December 942 at Picquigny on an island on the Somme, William was ambushed and killed by followers of Arnulf while at a peace conference to settle their differences. Family William had no children with his Christian wife Luitgarde. He fathered his son, Richard, with Sprota. his wife more danico''. Richard, then aged 10, succeeded as Ruler of Normandy upon William's death in December 942. Notes References External links Planctus for William Stewart Baldwin on Guillaume "Longue Épée" of Normandy 890s births 942 deaths Burials at Rouen Cathedral Year of birth uncertain 10th-century Dukes of Normandy Dukes of Normandy House of Normandy 10th-century Normans 10th-century rulers in Europe Converts to Christianity from pagan religions Norman warriors