He was the elder son of Robert I of Grandmesnil by his wife Hawise d'Echaffour, a daughter of Giroie, Lord of Échauffour.
Following the Norman Conquest, King William the Conqueror gave Hugh 100 manors in recompense for his service, sixty-five of them in Leicestershire, in the Midlands.
As fierce battle raged, Hugh's horse leapt a bush during a cavalry charge and his bridle broke.
Hugh's horse immediately shied in fear and bolted in the opposite direction and carried its helpless master away from the English and back to the safety of his own lines.
In 1067 he joined with William FitzOsbern, 1st Earl of Hereford and Bishop Odo of Bayeux in the government of England, during the king's absence in Normandy.
He also was one of the Norman nobles who interceded with the Conqueror in favour of William's son Robert Curthose, and effected a temporary reconciliation.
According to a historian writing in 1906 Hugh rebuilt the castle in stone and repaired "the rude Saxon church."
Adelize, the wife of Hugh de Grandmesnil, died at Rouen in 1087, and was buried in the Chapter House of St. Evroult.
On the death of William the Conqueror, also in 1087, the Grandmesnils, like most of the Norman barons, were caught up in the civil war raging between his three surviving sons.
The inhabitants of Courci had built their oven outside the castle's fortifications, and it now lay midway between the main gate and the enemy's Belfry.
Then William Rufus arrived with a fleet in arms against his brother, and so Duke Robert and De Belesme simply retreated home.
Feeling his end approaching, in accordance with the common practice of the period, he took the habit of a monk, and died six days after he had taken to his bed on 22 February 1098 at Leicester.
It appears that Ivo de Grandmesnil was influenced by his brother Robert, who held the family lands in Normandy, and joined the faction fighting against Henry of England.
Unfortunately, this left the Duke's supporters high and dry and King Henry, 'a famously unpleasant individual' [citation needed] took note of his enemies, including the Grandmesnils (Morris).
King Henry bestowed the manors of Barwell, Burbage, Aston, Sketchley and Dadlington on Hugh de Hastings, as he set about getting rid of any baronial opposition.
The cronies of the king's court treated Ivo contemptuously, and courtiers openly called him 'ropedancer', a reference to his escape from Antioch.
Ivo approached Robert de Beaumont, Count of Meulan, to procure a reconciliation with the king, and to advance him 500 silver marks for his expedition.
Beaumont was also to give the daughter of his brother Henry, Earl of Warwick, in marriage to Ivo's son, Baron Hinckley, who was still in his infancy, and to restore to him his father's inheritance.
However Ivo died on his crusade to Jerusalem,[5] and when he did not return Robert de Beaumont broke his oaths and took control of the whole of Leicester.
Ivo's nephew and heir, Hugh de Grandmesnil, Baron Hinckley, never recovered the honour of Leicester.
The Domesday Book lists Hugh's lands in Leicestershire[2] in the following order: Wigston Magna, Sapcote, Frolesworth, Sharnford, Earl Shilton, Ratby, Bromkinsthorpe, Desford, Glenfield, Braunstone, Groby, Kirkby Mallory, Stapleton, Newbold Verdon, Brascote, Peckleton, Illston on the Hill, Thorpe Langton, Stockerston, Burton Overy, Carlton Curlieu, Noseley, Thurcaston, Belgrave, Birstall, Anstey, Thurmaston, Humberstone, Swinford, Bruntingthorpe, Smeeton Westerby, Lestone, Twyford, Oadby, Peatling Parva, Shearsby, Sapcote, Willoughby Waterless, Croft, Broughton Astley, Enderby, Glenfield, Sutton Cheney, Barlestone, Sheepy Magna, Cotesbach, Evington, Ingarsby, Stoughton, Gaulby, Frisby, Shangton, Stonton Wyville, East Langton, Great Glen, Syston, Wymeswold, Sileby, Ashby de la Zouch, Alton, Staunton Harold, Whitwick, Waltham on the Wolds, Thorpe Arnold, Market Bosworth and Barton in the Beans.
In Northamptonshire his lands include pieces in West Farndon, Marston Trussell, Thorpe Lubenham, Weedon Bec, Ashby St Ledgers, Osbern, Welton, Staverton and Thrupp Grounds.