The manor of Old Hurst was originally parcel of the manor of Slepe and was granted with Slepe (St Ives) to Ramsey Abbey by King Edgar in 974. With Woodhurst it probably became a separate manor in the 11th century but both of them continued tithings of the soke of Slepe. The manor of Old Hurst may perhaps be traced to Ingelran [de Auco], who with Everard and Pleines held 4 hides in Slepe of the Abbot of Ramsey in 1086. Ingelran's land seems to have passed to Roger Fitz Mowin, who made an agreement with Abbot Reynald (1114–30) regarding the old fee at Hurst which Ingelran had held, and a rent in Fordham which Turkill his uncle had owned. Roger was living in 1134, but by 1166 Ralph Mowin was holding, with another, 4½ hides in Hurst, possibly the 4 hides in Slepe referred to above.
William Mowin who conveyed land in Old Hurst to John Mowin in 1228, may have been a son of Ralph. Sir William Mowin, as one of the abbot's knights, in 1244 sent William his son and John his nephew in his stead to serve in Scotland. John Mowin, possibly the nephew of Sir William, was holding 2 hides in Old Hurst in 1251, and in 1272 brought an action against the Abbot of Ramsey and Prior of St. Ives as to the advowson of the church of Old Hurst, in which he claimed that Ralph his grandfather presented to the church in the time of Henry II. In the same year John Mowin the elder conveyed a messuage and 3 carucates of land in Old Hurst to John Mowin the younger and Ascelina his wife. John the younger was holding in 1281 and was a justice for gaol delivery in 1288. He was apparently succeeded by William Mowin who, with his wife Mabel, was dealing with the manor in 1328. Shortly after this date the manor, it seems, was conveyed to trustees on behalf of the Abbot of Ramsey. In this way it passed to Robert de Thorp, whose son Robert in 1349 made a charge of £40 on the manor formerly of William Mowin for the benefit of Philip de Brampton, chaplain, and Robert de Kendale, clerk. This rent charge was conveyed to Nicholas de York (Everwyk), clerk. In 1356 Gilbert de Warewyk, chaplain, and Nicholas de York received licence to alienate the manor of Old Hurst with other lands to the abbot and convent of Ramsey, and thus it became merged in the abbey possessions.

Mowin.
Or three cinqfoils and a quarter gules.
In 1535 the Abbot of Ramsey leased the site of the manor for eighty years at a rent of £7 to Ralph Clay, who conveyed his interest to Andrew Jenour of Great Dunmow. The manor was granted in 1544 to Sir William Parr, Lord Parr of Horton, at a rent of 44s. 8½d., but his interest reverted to the crown and in 1588 it was leased in reversion to John Pratt, groom of the Poultry; courts baron, views of frankpledge and other rights being reserved to the crown. In 1590 the reversion of the manor in fee was granted to George Gascoigne, to whom, and to his son Nicholas, the manor was leased by Andrew Jenour and Francis Browne of Old Hurst on 12 June 1605. On the following day George and Nicholas Gascoigne leased it to Kenelm, son of Andrew Jenour, who again leased it to George and Nicholas for forty years.

Gascoigne.
Argent a pale sable charged with a conger's bead or.
Sir Nicholas Gascoigne (knighted in 1603) died seised of the manor, which he held of the king in chief, in 1618. His son and heir John was then an infant, and Elizabeth his widow occupied the manor. In 1634 it was leased for 99 years to Henry Pigott. John obtained livery of his father's lands in 1637, and in 1639, with Elizabeth his wife, he conveyed the manor to Owen Brett and Charles Estcott, possibly in trust for John Fountayne, of Lincoln's Inn. On 25 April 1646 Fountayne begged to compound for delinquency in escaping from the Gatehouse, to which he had been committed by the House of Commons, and going to Oxford, three years before. In April 1647 he petitioned for release from continued imprisonment, and in July represented that it was impossible for him to set a value on his manor of Old Hurst, because during sequestration the houses there had been pulled down and the lands wasted. He was granted two months to inform himself of the value of Old Hurst manor and of his manor of Ampney St. Peters in Gloucestershire. The composition papers refer to his father-in-law Robert Davis, and to his younger children by his first wife, who had brought a great portion, which he settled upon them in 1642. He died on 4 June 1671, aged 70. His eldest son and heir, John, who had married Elizabeth, daughter and heir of Major John Monckton of Melton, died in 1680, and bequeathed his estates to his brother Thomas Fountayne, who in the same year dealt with the manor.
The manor apparently passed to the daughters of Thomas Fountayne's brother John, namely Elizabeth wife of Sir Richard Osbaldeston, and Theodosia wife of Robert Monckton, who were holding in 1694. In 1711 it was in the hands of John Fountayne (who had succeeded his father Thomas at his death in 1709), and who dealt with the manor in 1713. He died in 1736 leaving four sons, the eldest of whom, Thomas, died without issue in 1739. The latter's brother John Fountayne, D.D., Dean of York, was holding the manor in 1780. As lord of the manor he received an allotment of land at the inclosure of Somersham Heath in 1796, and at the inclosure of Old Hurst common fields in 1801. The Dean of York died in 1802, his heir being his only surviving grandson, Richard Fountayne Wilson, son of his daughter Elizabeth, wife of Richard Wilson. Richard Fountayne Wilson died in 1847, and his second son, James, of Elm and of Melton Park, Doncaster, who took the name of Montagu under the will of the Rt. Hon. Frederick Montagu of Papplewick, held the manor until his death in 1891, when he was succeeded by his son, Frederick James Osbaldeston Montagu.

Fountaine.
Or a fesse gules between three elephants' beads sable.

Wilson.
Sable a leaping wolf or and in the chief three stars argent and a quarter or charged with a cross formy gules.

Montagu.
Argent a fesse indented of three points gules and a border sable.
It seems there were originally three Hursts in the manor of Slepe or St. Ives, Old Hurst, Woodhurst and Derhurst, the distinguishing prefixes first appearing in the 13th century.
The manor of DERHURST was held by a family that ultimately took the name of Hawker but was known indifferently as le Ostricer, Ostriciarius, Accipitrarius, and le Haucker. The manor was held in chief of the king by the serjeanty of keeping a goshawk for the use of the king at his expense. William Rufus (1091–1100) ordered William son of Osmund to return to the Abbot of Ramsey land in Hurst and to remove his falconry there. The order was repeated by Henry I who directed William the Hawker to repossess Abbot Aldwin of the land in Hurst of which he had deprived him. Sewin the Hawker and Alwan his wife were holding lands in Needingworth and Slepe in 1102–7. Baldric le Ostricer or Haucker died in 1232 seised of lands in Slepe held of the king in chief when Roger his son and heir did homage for them. Roger was holding the serjeanty in 1261, but in 1262 Alan le Ostricer did homage for the lands of his father Robert, possibly a brother of Roger. Alan died in 1274 seised of a messuage and carucate of land in St. Ives held by the serjeanty of keeping a goshawk. He left a widow Maud and a son Simon then aged eight years, whose wardship was given to the prior of St. Ives. Simon le Haucker died in 1303 holding by the same service and leaving a widow Alice and a son John aged nineteen years. In 1317–18 John le Hawker and Nicholas his brother, Maud widow of Alan le Hawker and Alice, widow of Simonle Hawker, joined in selling certain lands of the manor to William de Corton. In 1318 William de Corton conveyed his holding to the Abbot of Ramsey for finding a chaplain in the church of St. Benedict of Ramsey to pray for the said William, his ancestors, the king and others. The abbey, however, was to be free from such obligation if it supplied a chaplain to celebrate divine service in the chapel of the manor of Derhurst in the village and parish of Slepe or if that chapel should be ruinous, in the parish church of Slepe. The manor was at the same time sold by John le Hawker for 500 marks to the Abbot of Ramsey who assigned the profits from it to the new work of the church. The manor thus became absorbed into the possessions of the Abbey of Ramsey. It was attached to the office of chamberlain and was let from time to time as the lands late of John Haucker.
Another property was held by a family who bore the local name. In 1251 Yvo de Hurst held 4 virgates of land in Old Hurst of the manor of St. Ives. He or another of the same name was holding in 1281 and in 1303; while in 1302 Thomas son of Thomas de Hurst occurs. In 1306 land in Old Hurst was granted by Richard de Molesworth to Yvo son of Thomas de Oldhurst, and in 1318 Roger de Hurst was a tenant of the manor. This estate may perhaps be identified with the manor in Oldhurst which John de Lancaster and Mabel his wife demised to the Abbot of Ramsey in 1343.
An inclosure Act for dividing and inclosing the open fields and commonable places in Old Hurst was passed in 1801. Compensation was made under this Act to Sir Robert Burton, lord of the manor of Woodhurst from such part of Somersham Heath as had been allotted to Old Hurst at the inclosure of that heath, in lieu of certain ancient foldage rights belonging to Old Hurst, and from the same source to John Fountayne, lord of the manor, in lieu of his rights in the waste lands.
Victoria County History of Huntingdonshire - Printed 1932