Guillaume de Mortain

Guillaume de Mortain († about 1140), was Count de Mortain (1090-1106) and Count de Cornouailles (1090-1104). Because of its quarrel with Henry I {{er}} Beauclerc, it passed most of its life in prison.

He was the son of Robert de Mortain († 1090), half-brother and Compagnon of the Conqueror, and Mathilde de Montgommery. He was probably born between 1060 and 1074. He was of a temperament quite different from his father, and resembled more his turbulent uncle Odon of Bayeux.

Of its childhood, it keeps a hatred of his cousin Henri, the future Henri Ier Beauclerc. With died of his father, it not only requires to inherit the possessions of his father, but also the county of Kent which had belonged to his/her uncle Odon of Bayeux. In 1103, it turns over in Normandy and revolts openly against the king. Consequently, in 1104, it loses all its English strongholds and titles.

It is captured with Robert Courteheuse, Duc of Normandy, with the Bataille of Tinchebray and is imprisoned during long years, probably until the death of the king in 1135. After which he was monk with the abbey of Bermondsey (Ordre of Cluny) until his death in 1140.

He would have married Adilildis, and died without descent.

References

Robert, count de Mortain, and earl of Cornwall
Counts de Mortain

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