Editing William the Conqueror (section)

=== Consolidation of power ===

William's next efforts were against Guy of Burgundy, who retreated to his castle at [[Brionne]], which William besieged. After a long effort, the duke succeeded in exiling Guy in 1050.<ref name=Douglas54>Douglas ''William the Conqueror'' pp. 54–55</ref> To address the growing power of the Count of [[County of Anjou|Anjou]], [[Geoffrey Martel]],<ref name=Douglas56/> William joined with King Henry in a campaign against him, the last known cooperation between the two. They succeeded in capturing an Angevin fortress but accomplished little else.<ref name=Bates43>Bates ''William the Conqueror'' pp. 43–44</ref> Geoffrey attempted to expand his authority into the county of [[Maine (province)|Maine]], especially after the death of [[Hugh IV of Maine]] in 1051. Central to the control of Maine were the holdings of the [[House of Bellême|Bellême family]], who held [[Bellême]] on the border of Maine and Normandy, as well as the fortresses at [[Alençon]] and [[Domfront, Orne|Domfront]]. Bellême's overlord was the king of France, but Domfront was under the overlordship of Geoffrey Martel and Duke William was Alençon's overlord. The Bellême family, whose lands were quite strategically placed between their three different overlords, were able to play each of them against the other and secure virtual independence for themselves.<ref name=Douglas56>Douglas ''William the Conqueror'' pp. 56–58</ref>

[[File:Bayeuxtapestryodowilliamrobert.jpg|thumb|Image from the [[Bayeux Tapestry]] showing William with his half-brothers. William is in the centre, Odo is on the left with empty hands, and Robert is on the right with a sword in his hand.]]

On the death of Hugh of Maine, Geoffrey Martel occupied Maine in a move contested by William and King Henry; eventually, they succeeded in driving Geoffrey from the county, and in the process, William secured the Bellême family strongholds at Alençon and Domfront for himself. He was thus able to assert his overlordship over the Bellême family and compel them to act consistently with Norman interests.<ref name=Douglas59>Douglas ''William the Conqueror'' pp. 59–60</ref> However, in 1052 the king and Geoffrey Martel made common cause against William as some Norman nobles began to contest William's increasing power. Henry's about-face was probably motivated by a desire to retain dominance over Normandy, which was now threatened by William's growing mastery of his duchy.<ref name=Douglas63>Douglas ''William the Conqueror'' pp. 63–64</ref> William was engaged in military actions against his own nobles throughout 1053,<ref name=Douglas66>Douglas ''William the Conqueror'' pp. 66–67</ref> as well as with the new Archbishop of Rouen, [[Mauger (archbishop of Rouen)|Mauger]].<ref name=Douglas64>Douglas ''William the Conqueror'' p. 64</ref>

In February 1054 the king and the Norman rebels launched a double invasion of the duchy. Henry led the main thrust through the [[county of Évreux]], while the other wing, under the king's half-brother Odo, invaded eastern Normandy.<ref name=Douglas67>Douglas ''William the Conqueror'' p. 67</ref> William met the invasion by dividing his forces into two. The first, which he led, faced Henry. The second, which included some who became William's firm supporters, such as [[Robert, Count of Eu]], [[Walter Giffard, Lord of Longueville|Walter Giffard]], [[Roger of Mortemer]], and [[William de Warenne, 1st Earl of Surrey|William de Warenne]], faced the other invading force. This second force defeated the invaders at the [[Battle of Mortemer]]. In addition to ending both invasions, the battle allowed the duke's ecclesiastical supporters to depose Archbishop Mauger. Mortemer thus marked another turning point in William's growing control of the duchy,<ref name=Douglas68>Douglas ''William the Conqueror'' pp. 68–69</ref> although his conflict with the French king and the Count of Anjou continued until 1060.<ref name=Douglas75>Douglas ''William the Conqueror'' pp. 75–76</ref> Henry and Geoffrey led another invasion of Normandy in 1057 but were defeated by William at the [[Battle of Varaville]]. This was the last invasion of Normandy during William's lifetime. In 1058, William invaded the [[County of Dreux]] and took [[Tillières-sur-Avre]] and [[Thimert]]. Henry attempted to dislodge William, but the [[siege of Thimert]] dragged on for two years until Henry's death. The deaths of Count Geoffrey and the king in 1060 cemented the shift in the balance of power towards William.<ref name=Bates50>Bates ''William the Conqueror'' p. 50</ref>

[[File:Acrdwnch.jpg|thumb|left|The signatures of William I and Matilda are the first two large crosses on the [[Accord of Winchester]] from 1072.]]

One factor in William's favour was his marriage to [[Matilda of Flanders]], the daughter of Count [[Baldwin V of Flanders]]. The union was arranged in 1049, but [[Pope Leo IX]] forbade the marriage at the [[Council of Rheims]] in October 1049.{{efn|The reasons for the prohibition are not clear. There is no record of the reason from the Council, and the main evidence is from Orderic Vitalis. He hinted obliquely that William and Matilda were [[Affinity (Catholic canon law)|too closely related]], but gave no details, hence the matter remains obscure.<ref name=Douglas391->Douglas ''William the Conqueror'' pp. 391–393</ref>}} The marriage nevertheless went ahead in the early 1050s,<ref name=Douglas76>Douglas ''William the Conqueror'' p. 76</ref>{{efn|The exact date of the marriage is unknown, but it was probably in 1051 or 1052, and certainly before the end of 1053, as Matilda is named as William's wife in a [[charter]] dated in the later part of that year.<ref name=Douglas391>Douglas ''William the Conqueror'' p. 391</ref>}} possibly unsanctioned by the pope. According to a late source not generally considered to be reliable, papal sanction was not secured until 1059, but as papal-Norman relations in the 1050s were generally good, and Norman clergy were able to visit Rome in 1050 without incident, it was probably secured earlier.<ref name=Bates44>Bates ''William the Conqueror'' pp. 44–45</ref> Papal sanction of the marriage appears to have required the founding of two monasteries in Caen&nbsp;– one by William and one by Matilda.<ref name=Douglas80>Douglas ''William the Conqueror'' p. 80</ref>{{efn|The two monasteries are the [[Abbaye-aux-Hommes]] (or St Étienne) for men which was founded by William in about 1059, and the [[Abbaye aux Dames]] (or Sainte Trinité) for women which was founded by Matilda around four years later.<ref name=Bates66>Bates ''William the Conqueror'' pp. 66–67</ref>}} The marriage was important in bolstering William's status, as Flanders was one of the more powerful French territories, with ties to the French royal house and to the German emperors.<ref name=Bates44/> Contemporary writers considered the marriage, which produced four sons and five or six daughters, to be a success.<ref name=Douglas393/>