Manor of Isleworth Syon , Corporation of London

The Manor of Isleworth Syon has always been considered as coterminous with the hundred of Isleworth and included the parishes of Isleworth, Twickenham and Heston. At the time of the Domesday survey, in 1086, the manor was in the hands of Walter de St Valery, having been granted to him by William the Conqueror as a reward for his support during the conquest of England. The family retained possession of the manor until 1227 when it escheated to the crown.

In 1229 a full grant of the manor was made by Henry III to his brother, Richard, Earl of Cornwall, whose son Edward inherited it in 1272. In 1301, Edward's widow Margaret was assigned the manor by Edward I as part of her dower, but it reverted to the crown on her death in 1312.

The manor was eventually granted for life by Edward III to his wife Queen Philippa in 1330. The reversion was included in a grant of lands to Edward, Duke of Cornwall, in 1337. In 1390 Queen Anne the wife of Richard II was given a life interest in the manor. Henry V held the manor, as Prince of Wales, but when king, separated the manor from the duchy of Cornwall by Act of Parliament in 1421 in order to bestow it upon his newly founded convent of Syon. It remained as part of the convent's possessions until the dissolution in 1539 when it fell into the hands of the Crown and was added to the Honour of Hampton Court. In 1604 James I granted the manor to Henry, Earl of Northumberland, in whose family it remained.

One notable event in the later history of the manor occurred in 1656. In that year articles of agreement were drawn up between Algernon, Earl of Northumberland, lord of the manor of Isleworth Syon, and Sir Thomas Ingram and other principal copyhold tenants. These articles established certain of the customs of the manor on a firm basis. Fines and heriots were to be certain and not arbitrary, at the will of the lord. The tenure of customary and was to be by Borough English, whereby the youngest son of a copy holder inherited on the death of his father. These articles were signed on 20 May 1656 and were confirmed by a decree in Chancery, 28 June 1656. (see ACC/1379/330 and partial transcript in History of Syon and Isleworth by G. Aungier p.206) A printed tract called Isleworth Syon's Peace was to be published in 1657 and according to Aungier was to be placed in the Isleworth parish chest. He also refers to a copy in the British Museum. London Metropolitan Archives possesses a copy amongst the archives of the Earl of Jersey.

The manors of Worton and Aystones referred to in ACC/1379/12 originated in two freehold estates in the manor of Isleworth and were both connected with the Eyston Family. Together with other lands they were granted by Henry V to the Abbess and convent of Syon. (see Aungier, p. 212)

In the medieval period the manor of East Bedfont was held by the de Windsor family. From 1542 it was held by the Crown as part of the lands they owned around Windsor. The manor was customarily leased by both the de Windsors and the Crown. Tenants included the Trinitarian Priory at Hounslow, Lord Berkeley, and from 1656 the Earls of Northumberland.