He was Seigneur de Mortremer-sur-Eulane in NOrmandy.
The family of Mortemer derives its name from Mortemer (Mortuo-Mari) in
Pays-de-Caux at the source of the Eaulne River. The castle of St.
Victor-en-Caux was the chief barony of the family, which is said to have
sprung from a marriage of Walter de St. Martin and a niece of the Duchess
Gonnor. It was possessed by Roger de Mortemer in 1054, on which date he was
one of the commanders of Duke William's forces at the battle of Mortemer. He
sheltered in his castle, after the battle, his father-in-law, Raoul III. the
Great, Comte de Valois and d'Amiens, by Oderic Vital called de Montdidier, one
of the French commanders, until he was able to conduct him safely to his own
territories three days later. For this reason Roger was banished by Duke
William and his estates confiscated. He was later pardoned and his possessions
returned with the exception of the castle of Mortemer, which the Duke had
given to Roger's brother, William de Warren I. He contributed sixty vassals to
the fleet of Duke William and it is generally conceded that he was too old to
have been present at Senlac, although he made a donation to the abbey of St.
Ouen in 1074 and died prior to the compilation of the General Survey. Wace
mentions "Hue de Mortemer" as having taken part in the battle. Many
commentators believe this to be an error, contending that Wace should have
chronicled Roger or his son, Ralph, or both, because the only recorded Hugh
was the son of Ralph and therefore too young to have participated in this
event. There is no proof, however, that if not of this branch of the family, a
Hugh could not have sprung from another. Eyton says, "There is evidence that
Roger had two sons in addition to Ralph, namely, Hugh and William."
Nevertheless, Ralph was certainly Roger's heir, and if the son of Hawisa, the
only known wife of Roger, he must have been young at the time he attended the
Conquest. He possessed at the compilation of Domesday 123 manors, in addition
to the castle of Wigmore, in Herefordshire, which was the chief seat of his
barony. In 1088 Ralph was opposed to William Rufus in favor of Robert Curthose
(Courteheuse), but two years later, being pardoned, he accompanied Robert,
Count of Eu, and Walter Giffard to Normandy, where they arrayed themselves
against Duke Robert. In 1100 he founded the priory of Wigmore, at which time
it was stated that Roger de Mortemer, descended from his family. Ralph, by his
wife Millicent, had issue, Hugh, who succeeded him, William, to whom his
brother gave Chelmarsh and who was ancestor of the Mortimers of Attleborough
and Hawise, who married Stephen, Comte of Aumale. From this family descended
the Lords of Wigmore, Earls of March, Lords Mortimer of Richard's Castle, etc.
(Reference: Crispin & Macary, "Falaise Rolls").
1. Roger de Mortimer, the first of this name upon record is deemed by some to
have been the son of William de Warren, and by others, of Walter de St.
Martin, brother of that William. Which Roger was the founder of the abbey of
St. Victor, in Normandy. "It is reported," says Dugdale, "that in the year
1054 (which was twelve years before the Norman Conquest), when Odo, brother of
Henry, King of France, invaded the territory of Evreux, Duke William sent this
Roger, then his general (with Robert, Earl of Ewe, and other stout soldiers),
to resist his attempts; who meeting with Odo near to the castle of Mortimer,
gave him battle, and obtained a glorious victory. It is further observable of
this Roger, that he was by consanguity allied to the Norman duke (Afterwards
King, by the name of William the Conqueror), his mother being niece to
Gunnora, wife of Richard, Duke of Normandy, great grandmother to the Conqueror.
" The presumed son of this Roger, was Ralph de Mortimer.