on the history of the Earldom of Huntingdon:
The first post-Conquest Earl of Huntingdon appears to have been Waltheof, son of Siward Earl of Northumberland and indeed Siward's successor in the latter Earldom as well. Waltheof was later beheaded for conspiring against William the Conqueror. [Burke's Peerage]
-------------------------------
EARLDOM OF NORTHAMPTON (I)
EARLDOM OF HUNTINGDON (I)
WALTHEOF, son of SIWARD, EARL OF NORTHUMBERLAND, by lfled, daughter of ALDRED of Bernicia, became EARL OF HUNTINGDON and EARL OF NORTHAMPTON when Tostig was banished in October 1065. He is not known to have opposed the Conqueror in 1066, but was taken to Normandy the following year. In 1069 he joined the Danes in their descent on Yorkshire, distinguishing himself in the attack on the city of York. When the Danes left England he submitted himself to William, in January 1070, and was restored to his Earldom, and to his father's Earldom of Northumberland in 1072. While attending the wedding of Ralph de Gael, Earl of Norfolk, at Exning in the spring or summer of 1075, he was enticed to join the conspiracy of the Earls of Norfolk and Hereford to seize England for themselves. He quickly repented, and by Lanfranc's advice went to Normandy and asked pardon of the King, who treated the matter lightly at the time; but at Christmas Waltheof was brought to trial at Westmminster, his wife Judith being a witness. He was imprisoned at Winchester, where on the resumption of the trial in May he was condemned and beheaded on St. Giles's Hill, 31 May 1076, and hastily buried .
He married, in 1070, Judith, daughter of Lambert, COUNT OF LENS, by Adelaide or Adeliz, sister of the Conqueror. He died as aforesaid, 31 May 1076, and a fortnight later the Abbot Ulfketel, at Judith's request and by the King's permission, removed his body to Crowland, where it was honourably entombed.(g) His widow, who as "Judith the Countess" is recorded in Domesday Book to have held estates in many counties in 1086, most of them apparently gifts from the King, her uncle, held Huntingdon in dower. She founded the Nunnery of Elstow, near Bedford. [Complete Peerage VI:638-40, (transcribed by Dave Utzinger)]
[g] Many miracles are recorded, for Waltheof was by many regarded as a saint. An epitaph was written for the tomb by Orderic. Other epitaphs are in the Vita. He is described as strong in person and of great repute as a warrior, pious had learnt the psalter in his youth, was liberal to the clergy and the poor, and a benefactor in particular to Jarrow and Crowland. To the former he gave Tynemouth. The chief stain on his memory is his part in a family bloodfeud, for he ordered the murder of the sons of one Carl, who had killed Earl Ealdrcd, Walthcof's grandfather.
------------------------------------
The county which gives designation to this earldom of Huntingdon was, according to Dr. Heylin, a thickly wooded forest until the reign of the 2nd Henry, when the timber was first cleared away; the chief town, from the celebrity of the forest as a chase, was called Huntingtown, which soon became abbreviated into Huntington, or Huntingdon. The Earldom of Huntingdom was conferred by William the Conqueror upon Waltheof (son of Syward, the Saxon Earl of Northumberland), who had m. the dau. of that monarch's sister, by the mother's side, Judith. He was also Earl of Northampton, and of Northumberland, but conspiring against the Normans, he was beheaded in 1073 at Winchester, leaving issue, Maud and Judith. [Sir Bernard Burke, Dormant, Abeyant, Forfeited, and Extinct Peerages, Burke's Peerage, Ltd., London, 1883, p. 467-8, St. Liz, Earls of Huntingdon]
------------------------------------
Waltheof was the last of the Old English earls to survive under William I, his execution for treason in 1076 marking a significant stage in the aristocratic and tenurial revolution which followed 1066. Younger son of Siward, the Danish earl of Northumbria (1041-55) and Aelflaed, daughter of Aldred, earl of Northumbria, Waltheof received an earldom consisting of the shires of Huntingdon, Bedford, Northampton, Rutland, and Cambridge in 1065. As one of the few English magnates not from the Godwin faction, he accepted and was accepted by William I, witnessing royal charters and remaining loyal to the new regime until 1069 when he joined with the Danes in their invasion of Northumbria. He was prominent in their capture of York, hoping, no doubt, to be restored to his father's position. This opportunism is perhaps more characteristic of English magnate reactions to the political turmoil of 1065-70 than any supposed national feeling. However, the revolt and invasion were defeated by William's winter campaign of 1069-70. It is a measure of William's insecurity that when Waltheof submitted in 1070 he was restored to royal favour and, in 1072, added the earldom of Northumbria to his holdings. To bind him more tightly to the Norman dispensation, William gave him his niece Judith in marriage. But in 1075, Waltheof was implicated in the largely French revolt led by Ralph, earl of Norfolk, and Roger, earl of Hereford. Despite his lack of military action, his confession, apparent contrition and the support of Archbishop Lanfranc, Waltheof was executed on 31 May 1076.
The king's motives are obscure. Waltheof was the only prominent Englishman to be executed in the reign. Perhaps his removal was part of William's justifiably nervous response to the problem of controlling Northumbria. It may have made sense to take the chance to remove a potential --- and proven --- focus of northern discontent. Yet Waltheof's heirs were not harried, one daughter, Matilda, marrying David I of Scotland (1042-53), and another Ralph IV of Tosny, a leading Norman baron.
Waltheof is a significant reminder that the period around 1066 was transitional, with no necessarily definite beginnings or endings. Waltheof adapted to the new order, falling foul, it seems, of the ambitions and schemes of others, not least of parvenus Frenchmen. He married into the new elite, yet embodied the old. Heir to both English and Anglo-Danish traditions, it was he who completed one of the most celebrated of Anglo-Saxon blood-feuds. In 1016, Uchtred, earl of Northumbria was murdered by a northern nobleman called Thurbrand. He was, in turn, killed by Uchtred's son and successor, Ealdred, who was himself slain by Thurbrand's son, Carl. Waltheof's mother was Ealdred's daughter and he avenged his great-grandfather and grandfather by massacring a number of Carl's sons.
Waltheof was buried at Crowland Abbey where, as did many martyrs to royal policy in the middle ages, he found posthumous fame in a cult which, by the mid-twelfth century, was venerating him as a saint. Yet his career in the north shows that not far beneath the measured tones of Norman propagandists or the efficient gloss of English bureaucratic procedures simmered the violence of Dark Age epic. [Who's Who in Early Medieval England, Christopher Tyerman, Shepheard-Walwyn, Ltd., London, 1996; EncyclopEdia Britannica CD, 1997]