Boding the constable held, and could sell, the manor of GRENDON before the Conquest. In 1086 it formed one of the two manors held in this county by Henry de Ferrers. No further record of the latter's lordship is evident, however. It is probable that the overlordship belonged to the honour of Wallingford in the 12th century, being attached to it possibly by Henry II, when the manor was in the Crown.

Later, the overlordship rights were certainly exercised by the Earl of Cornwall, though whether the manor was attached to his honour of Wallingford or to that of St. Valery appears to have been very imperfectly known, as various 14th-century documents ascribe it to one or other indiscriminately. The confusion may have been partly due to the similarity of service by which Grendon and an Oxfordshire manor were held of the Earl of Cornwall. Both manors were held by the same tenant, Henry Tyes, some time in the 13th century, and after he lost Grendon he retained the Oxfordshire manor, for which in 1300 he rendered to the honour of St. Valery an ebony bow and three barbed arrows or 12d. yearly. This identical service was also due from Grendon from the 13th to the end of the 15th century, and it seems likely that similarity of overlord, tenant and service may have caused confusion as to which particular honour the manor was attached. It belonged to the honour of Wallingford as late as 1520 and in 1559 was held of the queen as of her honour of Ewelme, this being the last mention of the overlordship.

Henry de Ferrers himself held the manor in 1086, but by the time of Henry II it had come into the king's hands. In 1162–3 the Sheriff of Buckinghamshire rendered account of 1 mark from Grendon. During the years 1176–9 land here was held for 60s. yearly by Henry the king's 'cytharist' or harpist, whose descendants may have been the William le Harpur and Henry le Harpur who held half a virgate here in 1234.

At some period during the 12th century the main part of Grendon was held by Robert de Tyboville or Tibeville, a Norman, and valued in 1205, after his forfeiture, at £6, the stock consisting of eight oxen and two plough-horses.

Geoffrey le Sauser received the manor before 1210–12, and afterwards demised it to John Marshal. In 1228 the king promised that he would not disseise John as long as he should be in Ireland on the king's service. The following year the king granted the manor to Thomas Basset 'to sustain himself in the service of the king for as long as pleased him,' on condition that as long as he held it he should pay 100s. rent annually from the land to Geoffrey le Sauser. At the same time John Marshal was allowed to reserve his stock and the corn he had sown on the land.

Thomas Basset, however, had either died or given up the land before the end of 1230, when it was granted to Henry Tyes (Teutonicus), who was to hold it until the king should restore it to the right heirs by a peace or by his free will.

Henry was still in possession in 1234, but it was held soon after this date by Ralph de St. Amand, who died in 1245–6. His son Aumary de St. Amand, who succeeded him in the manor, was 'amerced in the Court of King's Bench as a Baron' in 1279–80 and died about 1285, leaving a son a heir Guy. The latter died soon after, while still a minor, and his widow Lucy received a grant as dower in 1287. His heir was his brother Aumary, to whom Grendon was restored, Lucy receiving another manor in exchange.

The manor then followed the descent of the barony of St. Amand until its abeyance in 1402, when the heirs of Aumary Lord St. Amand were his younger daughter Ida who died without issue and Gerard Braybroke, son of his elder daughter Eleanor. His widow died in 1426, when the daughters and heirs of Gerard Braybroke inherited.

Of these Maud, wife of John Babyngton, died in the same year, leaving her two sisters as co-heirs to her portion. One of these, Eleanor Braybroke, died unmarried two years later. The other, Elizabeth, married William Beauchamp and held the manor until her death in 1491.

Her son and heir Richard Beauchamp, who, like his father, bore the title of Lord St. Amand, was attainted in 1483, but was restored in 1485, by Henry VII. He had no lawful issue, but at his death in 1508 left the manor to his illegitimate son Anthony. In 1520 Anthony St. Amand conveyed the manor to John Cheyne and others, trustees of Thomas Pigott of Whaddon, who died later in that year.

Grendon was then held by the trustee, Sir Richard Sacheverell, kt., and after the death of Elizabeth Pigott, the widow, about 1549 it passed, by the terms of Thomas's will, to their eldest son Thomas. Doddershall in Quainton (q.v.) also came to this son, and the two manors then descended together until about the middle of the 19th century, when William Pigott sold the manor of Grendon to one of the Jervoise family, presumably George Purefoy Jervoise, whose father, the Rev. George Huddleston Purefoy Jervoise, had already in 1796 bought a large part of the Pigotts' lands here and left them at his death in 1805 to his son the above George Purefoy Jervoise.

At the death of this George Purefoy Jervoise in 1847 his estates devolved on his sister and heir Mary Purefoy Jervoise, whose husband, the Rev. Francis Ellis, assumed the additional name of Jervoise in 1848. Their son Francis Jervoise Ellis-Jervoise was lord of the manor in 1869.

Before 1873, however, the manor had returned to the Pigott family, being held then and afterwards by the Rev. R. H. Pigott. Mrs. R. H. Pigott is now lady of the manor.

A messuage appurtenant to the manor was recorded to be worth 5s. per annum with a curtilage in 1285. In 1310 it was valued at 2s. only because the house was falling down, but by 1333 it had evidently been rebuilt, as it was then worth 6s. 8d. annually.

In 1234 the king's officer was ordered to let Henry Tyes take thirty logs in Grendon Wood to make a windmill, and this, or its successor, was included among the appurtenances of the manor in the 17th and 18th centuries. In 1333 mention is made of a certain tallage called 'Cristmesseyelde' payable by the lord of the manor at Christmas.

As early as the 13th century the Abbot of Reading held land in Grendon in free alms of the gift of John de Hannay, chaplain, who had granted to the monastery a small estate here. Henry de Scaccario afterwards held this land under the abbot, paying 5s. annually, and in 1253 Ralph de Scaccario subinfeudated this estate to Robert of Grendon, clerk, son of Henry Tyes, who held it as 1 hide in 1254–5. In 1271 Robert for 20s. yearly granted his interest in a messuage and 6 virgates to Geoffrey le Fraunceys and Margery his wife, who were to hold after the donor's death of the chief lords. In 1291 the abbey's lands here were still valued at 5s., but there is no trace of them at the Dissolution.