• Born: 1027, Château de Falaise, Calvados, Normandy, France
• Married (1): 1040
• Married (2): 1050/2, Cathedral of Notre Dame, Eu, Normandy, France
• Died: 9 Sep 1087, Prioré de Saint-Gervais, Rouen, Normandy, France
• Buried: Abbey of St Step, Caen, Calvados, France

  Research Notes:

William was the illegitimate son of Robert, Duke of Normandy.

Guillaume of Jumièges records that “Roberto Duce...Willelmum filium suum” was born “apud Falesiam”. His birth date is estimated from William of Malmesbury, according to whom Guillaume was born of a concubine and was seven years old when his father left for Jerusalem, and Orderic Vitalis, who states that he was eight years old at the time. Deville suggests that Guillaume´s birthdate can be fixed more precisely to [mid-1027], taking into account that his father Robert occupied Falaise immediately after the death of his father Duke Richard II (23 Aug 1026), not wishing to accept the authority of his older brother Duke Richard III, but that Robert´s stay was short as the two brothers were reconciled soon after, it being reasonable to suppose that Robert´s relationship with Guillaume´s mother occurred soon after his arrival at Falaise. According to Orderic Vitalis, Alain III Duke of Brittany was appointed his guardian during his father's absence in 1035.

He succeeded his father in 1035 as GUILLAUME II Duke of Normandy. Orderic Vitalis records that, after the death of Duke Robert in 1035, “Willermus filius eius...octo annorum” succeeded and held “ducatum Normannorum” for fifty-three years. After Duke Alan was poisoned, Orderic Vitalis records that Gilbert Comte d'Eu was appointed guardian but was himself murdered. Duke Guillaume helped Henri I King of France to defeat Geoffroy II "Martel" Comte d'Anjou at Mouliherne in [1045/55]. Edward "the Confessor" King of England may have acknowledged Guillaume's right to succeed to the English throne on several occasions, maybe for the first time during a visit to England in 1051 which is recorded in the Anglo-Saxon Chronicle.

Comte du Maine 1063, after he conquered the county. In [1064/65], Duke Guillaume interceded with Guy de Ponthieu Comte d'Abbeville to secure the release of Harold, son of Godwin, in return for Harold's acknowledgement of Guillaume as successor to the English throne according to the portrayal of the event in the Bayeux tapestry. Harold's visit to Normandy, and swearing allegiance to Duke William, is recorded by William of Jumièges. According to Eadmer of Canterbury, the reason for Harold's visit was to negotiate the release of his brother Wulfnoth and nephew Haakon, both of whom had been hostages in Normandy since 1051. On his deathbed King Edward "the Confessor" bequeathed the kingdom of England to Harold. Duke Guillaume branded Harold a perjurer and appealed to Pope Alexander II for support. After receiving a papal banner in response to this request, William gathered a sizable army during summer 1066 ready for invasion. After some delay due to unfavourable weather conditions, the army set sail for England from Saint-Valéry-sur-Somme 28 Sep 1066. He defeated and killed King Harold at Hastings 14 Oct 1066, and made his way to London where he was crowned 25 Dec 1066 as WILLIAM I "the Conqueror" King of England at Westminster Abbey, possibly by Ealdred Archbishop of York who may have officiated because of doubts concerning the validity of the appointment of Stigand as Archbishop of Canterbury. The latter had received his pallium in 1058 from Pope Benedict X, later regarded as anti-Pope, an appointment which had not been regularised by Pope Alexander II. Orderic Vitalis records that King William was crowned again at Winchester by “cardinales Romanæ ecclesiæ...Alexander papa...vicarious: Ermenfredum pontificem Sedunorum et duos canonicos cardinales”, dated to 1070. After taking several years to subdue the whole country, he imposed the Norman feudal structure and rule everywhere with methodical and harsh persistence. The minute description of the country contained in the Domesday Book, completed in 1086, enabled King William to create an effective tax base.

Orderic Vitalis records the death “V Id Sep Rotomagi” 1087 of “Guillelmus Nothus rex Anglorum” and his burial “in ecclesia sancti Stephani...Cadomi”. He died from wounds received at the siege of Mantes, having been injured internally after being thrown against the pommel of his saddle, leaving Normandy to his eldest son Robert and England to his second surviving son William. Florence of Worcester records the death "Id Sep V" of King William and his burial "Cadomi in ecclesia S Stephani Protomartyris". The Brevis Relatio de Origine Willelmi Conquestoris records that "Willelmus…Roberti filius" was buried "Cadomi in ecclesia beati Stephani" which he had built. ¹