William Fitzosbern, 1st Earl of Hereford - History provided in Find a Grave

The following extensive history is from FindAGrave - I'm not sure where to place it - could someone advise
Birth: 1016
Poitiers, France
Death: Feb. 22, 1071
Denain, France

Lord of Breteuil, Normandy, Earl of Hereford, Gloucester, Worcester and Oxfordshire

William FitzOsbern was the son of Osbern de Crepon, the Steward, and Albreda de Bayeau. Grandson of Herfast. He was also the nephew of Gunnora, Duchess of Normandy, second wife of Richard I of Normandy. Brother of Osbern, Bishop of Exeter.

William married Adeliza de Toeni, the daughter of Roger de Toeni and Adelaide of Barcelona. They had the following children, and she died before 1066:
* William, Lord of Breteuil
* Roger de Breteuil
* Emma FitzOsborne, wife of Ralph de Guarder

It is said William married Richilde, Countess of Hainhaut, before his death, but had no issue.
William FitzOsbern became one of the great magnates of early Norman England, created Earl of Hereford before 22 February 1067, one of the first peerage titles, and was known to be one the greatest castle builders.

His father was the steward of his cousin Duke Robert I of Normandy. When Robert gave his duchy to his young son, William (the Conqueror), Osbern was one of Duke William's guardians. Osbern was killed in William's bedroom, defending the boy against an assassination attempt around 1040. Osbern's properties in Normandy, including the honors of Pacy and Breteuil, inherited through his wife, the daughter of the half brother of Duke Richard I of Normandy, was passed on to his son, William FitzOsbern.

William FitzOsbern, like his father, became a the ducal stewards, one of the first and adamant supporter to the invasion, known to have convinced the skeptical barons the invasion was truly possible.

During the invasion, it was recorded that "William FitzOsber" interrupted the Duke's lecturing his troops with, "Sire, we tarry here too long, let us all arm ourselves. Allons! Allons!" and his horse was said to have been covered in iron, which would not have been normal for that time.

After the invasion, and the Duke became William I, FitzOsbern was given the charge of the Idle of Wight, and made Earl of Hereford, Gloucester, Worcester and Oxfordshire. He was appointed Mayor of York after Edgar Ætheling's defeat. The King returned to Normandy in 1067, leaving the control, and further conquests of England to FitzOsbern and Odo de Bayeaux.

FitzOsbern would accompany the King after his return to the conquests of south western England, attended the King's Whitsunday in May of 1068, receive the charges of the new castle at York in 1069, and attend the King's Easter court in April before the conquest of Gwent in Wales.

FitzOsbern was one of the major Norman castle builders, having the castles of Carisbrooke on the Isle of Wight, Chepstow or Striguil, Wigmore, Clifford Castle and Monmouth Castle attributed to him, along with fortifications in Hereford and Shrewsbury.

Meanwhile, King William's wife's brother, Baldwin, Count of Flanders, died, leaving Flanders to his son with his wife, Richilde, as regent. Her husband's brother, Robert the Frisian, disputed the boy's claim to Flanders. Richilde offered her hand in marriage to the now powerful William FitzOsbern, eager to accept and become Count of a rich empire next door to Normandy. William and his army met the forces of Robert the Frison at Ravenchoven in the Battle of Cassel on 22 February 1071. He fought alongside armies sent by Philip I, King of France to support Richilde and her son, Arunulf, who was killed in the battle as well. Richilde and Robert were both taken captive, later exchanged, and Robert ruled Flanders as Robert I.

According to Meier, one of William's own knights, Gerbod, unhorsed William before killing him, but no motive is known. William's body was carried by his men to the Abbey of Cormeilles, in Normandy, of which he was the founder in 1060, and buried there "amid much sorrow."

His eldest son, William,, Lord of Breteuil succeeded him in Normandy, while his younger son, Roger, inherited Clifford Castle and all William's English holdings.

Family links:
Spouse:
Adeliza De Toeni FitzOsbern (1035 - 1066)

Children:
William de Breteuil (____ - 1104)*