Mabel FitzHamon of Gloucester

Mabel FitzRobert, Countess of Gloucester (1090 – 29 September 1157) was an Anglo-Norman noblewoman, and a wealthy heiress who brought the lordship of Gloucester, among other prestigious honours to her husband, Robert, 1st Earl of Gloucester upon their marriage. He was the illegitimate son of King Henry I of England.

Her father was Robert Fitzhamon, Lord of Gloucester and Glamorgan. As she was the eldest daughter of four, and her younger sisters had become nuns, Mabel inherited all of his honours and properties upon his death in 1107.

As Countess of Gloucester, Mabel was significant politically and she exercised an important administrative role in the lordship.

Mabel was born in Gloucestershire, England c1090 or later, the eldest of the four daughters of Robert FitzHamon, Lord of Gloucester and Glamorgan, and his wife, Sybil de Montgomery. Her three younger sisters, Hawise, Cecile and Amice all became nuns, making Mabel the sole heiress to her father's lordships and vast estates in England, Wales, and Normandy.

Her paternal grandfather was Hamon, Sheriff of Kent, and her maternal grandparents were Roger de Montgomery, 1st Earl of Shrewsbury and Mabel Talvas of Belleme.

In March 1107, her father died in Normandy, leaving his lordships and estates to Mabel. Her mother married secondly Jean, Sire de Raimes.

In 1107, Mabel married Robert of Caen,(also called FitzRoy and FitzEdith), an illegitimate son of King Henry I (not by his mistress Sybil Corbet - other sources say Robert's mother was of the Gai family of Oxfordshire). Their marriage is recorded by Orderic Vitalis who also names her parents. He would later become an important figure during the turbulent period in English history known as The Anarchy which occurred in the reign of King Stephen of England. Throughout the civil war, he was a loyal supporter of his half-sister Empress Matilda who would make him the chief commander of her army. He had originally sworn fealty to King Stephen, but after quarrelling with him in 1137, his English and Welsh possessions were forfeited, and thus he joined forces with Matilda.