Hugh "Blundus" FitzOsbern must have been born before 1040 or so, given that he was of age around 1066 (see quote below). As his Norman name suggests, he was the son of Osbert who we know basically nothing about.
He was still alive in 1086 when he witnessed a charter of Earl Hugh Lupus (Earl of Cheshire) and he must have died before 1119 (his son Osbert succeeded before that date).
From Barons1:
After the rebellion of Edwin and Morkere, William the Conqueror gave Chester the capital of the Mercian earldom, and its county, first to his stepson, Gherbod, and then, after Gherbod's crime and imprisonment in Flanders, to Hugh, the son of Richard Comte of the Avranchin and Hiemois. Hugh le Loup, as tradition, if not the usage of his own day, has nicknamed him, was almost as independent of the King of England as the Duke of Normandy of the King of France: his earldom was not subject to English law or taxation; he was the military executive and judicial leader of the whole county, and the universal landlord; enjoyed its entire revenues and profits, and in one of his charters speaks of the shiremoot as "my court."
One of these privileges afterwards termed regalian was that of supreme jurisdiction in all causes, capital or otherwise, over his vassals in his court at Chester. That which the Earl possessed be was able to delegate to others, and by granting such complete jurisdiction over their tenants to his greater barons (for all his tenants in chief like those of the King were then termed barons) he established territorial franchises or privileged tenures which within fifty years of his death were described as 'honours,' a word which signifies a barony in the more modern and limited sense. These barons, lesser and greater, seem for the most part to have been-not the hereditary vassals of his family in Normandy (for Richard, his father, was still living and in possession of Avranchin and Hiemois eleven years after Hugh had received the Earldom)-but rather younger sons of great houses who had attached themselves to him, either owing to relationship or because as the Conqueror's kinsman and favourite he was a man marked out for greatness. In other words, it was more of a personal than of a territorial following.
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Even the minor tenants in chief were men of great lineage; as for instance Baldric, whom Ormerod calls an obscure proprietor, but who can be proved brother to Richa:rd de Nevill and to Robert de Courci.
The number of the Cheshire barons (majores barones) has always been a disputed point, though I hope that it will soon be so no longer, and even Dugdale, while giving a list of some six or seven, has frankly acknowledged that there were a few others whom he had been unable to identify. Amongst these forgotten baronies that of Hugh Fitz Osbern was not the least important. I have, I am ashamed to say, failed to trace his family into Normandy, but according to the Cheshire genealogists, who have paid much attention to the subject, he and his neighbour and companion in arms, Osbern Fitz Tezzon, were both of the race of that great Raoul Taisson or Tesson, Seigneur de Cinqueleiz, and founder of the Abbey of Fontenay, who brought one hundred and twenty knights to the field of Val-es-Dunes in 1047, and is said to have been a descendant of the Counts of Anjou and to have held a third of all Normandy in fee. The proved descendants of this Raoul, as well as of Hugh and of Osbern, were landowners in Lincolnshire in the twelfth century; and the relationship between the two latter is probable enough, for their castles on the Welsh frontier were but two miles apart, their successors bore the same heraldic figure, the tinctures alone supplying a difference, and for generations appear with tedious monotony side by side in the lists of witnesses.
Hugh Fitz Osbern, however, was certainly not the same person as Hugh the son of Osbern Fitz Tezzon, with whom he has been confused, and it is quite possible that a wrong guess has been made, and that the two families were of distinct origin. The fact that neither Hugh nor Osbern bore a local surname renders it probable that they both were younger sons, and not in the possession of Norman fiefs, but in spite of that the contribution made by each to the conquest of Cheshire must have been very considerable to have deserved so rich a reward. No doubt both were of great lineage in Normandy, and I fancy that if Osbern the father of Hugh is ever identified he will be found to have been a member of one of those families which were nearly related to the Earl.
With Hugh Fitz Osbern my account must therefore begin. His possession of the manors of South Ormesby and Kettlesby (with its soke of Walmsgate) in Lincolnshire, into which we may reasonably conjecture he was infeuded by the Earl or his father soon after 1066, marks him out as one of those who left their Norman seigneuries to sail in the contingent of fifty boats which Richard d' Avranches (rather than bis son the future Earl) contributed to the invading fleet. Probably he gained these manors by service throughout the campaign which opened at Hastings; certainly he was one of the Earl's officers in the reduction of Cheshire in 1071 and 1072, and he will thus have played his part in that bloody battle of Nantwich, traditionally remembered even at the end of the fourteenth century as one wherein manors were lost by death and gained by valour. By such service, and no doubt by the largeness of his military following and of his contribution in money and munitions of war (for Norman conquerors in dividing the spoil considered the quantity rather than the quality of valour supplied), he gained that fief which the Domesday for Cheshire describes as lying in some fifteen (it should be eleven) separate townships. He is recorded as holding in 1086 the manors of Caldecote [the site of a Roman villa], Pulford, Wardle, Bosley, Marton, Kermingham, Sumreford, Allington, Eyton, Sutton, Broughton, Claverton, and Edritone; in Handbridge, now a suburb of Chester, he had an estate assessed at a carucate, and this reached up to the very foot of the bridge of Chester, a spot to which at fixed intervals all the military tenants of the county were marched under the command of the seneschals of the baronies, in order to take part in the show of weapons. He possessed also eight 'burgenses' in the city, and four beyond the water, a salt wich in Northwich, and five hides in Gresford.
The caput of Hugh Fitz Osbern's barony was Pulford, described by Randle Holme as "a castle aunciently built to represse the enimy the Welsh, where hath bin a family of the name, of which many have bin knights"....The last instance of its military use was in 1403, when Sir Thomas le Grosvenor, the heir of the Pulfords, had a mandate from Henry Prince of Wales to hasten to his possessions at Pulford, and elsewhere on the marches of Wales, there to make defence against the coming of Owen Glendower; but though it ceased after this date to have any strategic importance, there still remains between the church of Pulford and an angle of the brook which divides Cheshire from Wales, and partly serves the purpose of a moat, a strong semi-circular earthwork, within which is a mound or keep. The plan of the castle is very similar to those of the neighbouring defences on the Welsh frontier, and here no doubt Hugh Fitz Osbern and his heirs had a stockaded fortress and oaken hall, which, through centuries of border warfare, must have stood many a siege from the Welsh, and been the starting point of many a raid.
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In a record of the end of the twelfth century Hugh Fitz Osbern is distinguished. from his grandson, another Hugh Fitz Osbern, by the nickame of 'Blundus' or' The Fair,' and we learn from the same source that he had two sons, namely Osbert and Simon, the former of whom succeeded him, while to the latter he gave seven bovates of land in Moreton [near Timberland, co. Lincoln] for his homage and service.
From page 4 of the same source:
Blundus, in Norman 'Le Blount,' in English 'The Fair,' is in this case evidently a personal nickname, not borne by other members of the family, and there is no reason to connect the bearer with the great Norman house of that name.
Footnotes
[1] The Barons of Pulford in the 11th and 12th Centuries; George Sitwell, Scarborough, 1889; pages xi-xv
Est 1040 - 1119 (~ 46 years)