Isleworth, United Kingdom

Isleworth was a well-cultivated farming and trading settlement, more valuable than many of its neighbours at the time of the Norman Conquest in 1066. For centuries it continued to stretch from the Middlesex bank of the Thames in the east, west to include the centre of what was its hamlet then chapelry Hounslow (including the medieval founded Hounslow Priory) and to bound Whitton, as far north so as to bound Southall (in Hayes parish at the time), and as south as to bound Twickenham. The Domesday Book (1086) as Gistelesworde records its 55 ploughlands, 118 households and amount rendered, £72 per year, to its feudal system overlords. After the Conquest, successive Norman barons of the Saint Valeri family held the manor of Isleworth but there is no evidence that they lived there – it being held as a source of rentals and subinfeudation/lettings/charitable giving power. One of the later barons gave several manorial rents and privileges to London's Hospital of Saint Giles. He also gave the church and advowson to the Abbey of Saint Valeri, at the mouth of the Somme in Picardy.

In 1227, when he took control of England from his childhood regents, Henry III seized Isleworth manor and other property of the Saint Valeri family and gave the manor to his brother, Richard, 1st Earl of Cornwall. He built a new moated manor house, which is described in the Black Book of the Exchequer – having a tiled roof, chimney, two bedchambers and an inner courtyard. Outwith the moat was an outer courtyard with a number of buildings for servants and supplies, and a short distance away was a watermill. The exact location is unknown, but a report long ago of 'Moated Place' puts the likely place between the Northumberland Arms and Twickenham Road, with the watermill being near Railshead, on the only suitable water then existing, the Crane. The seemingly classic medieval manor house was burned down during the Second Barons' War in 1264.

The Abbey of Saint Valeri in Picardy held the livings (benefices) and revenues of several English parish church lands and, responding to growing disquiet over these foreign holdings, in 1391 it transferred those of Isleworth (for a fee) to William of Wykeham, who endowed them to Winchester College, which he founded. The Wardens and Scholars of Winchester College therefore became proprietors of productive rectory (which had glebelands). This lasted for 150 years, then in 1543 King Henry VIII exchanged with Winchester certain manors elsewhere for five churches in Middlesex, including All Saints.

Four years later he gave the Isleworth rectory and advowson to the Edward Seymour, 1st Duke of Somerset, but they returned to the crown when the Duke was executed in 1552. Soon after, they were given to the Dean and Canons of St George's Chapel, Windsor, with whom they remain today. The castle-like stone church tower by the river remains from this period, see below.

In 1415 Henry V granted nuns from the Swedish Bridgettine order land on the bank of the Thames, firstly in Twickenham opposite his new Sheen Palace, where they built their first house Syon Monastery. In 1422 Henry V transferred ownership of Isleworth Manor from the Duchy of Cornwall to Syon Monastery, which in 1431 was selected for the new site within their manor to rebuild their monastery. This is the site of the present Syon House.

Henry VIII demolished most of Syon Monastery after 1539 and the site and manor was granted to Edward Seymour, 1st Duke of Somerset. It was Seymour who built Syon House in 1548. Lady Jane Grey was taken from here to the Tower by Royal barge in anticipation of her being crowned Queen of England.

Forty-six years later, in 1594 Queen Elizabeth I granted a lease of the manor of Syon to Henry Percy, 9th Earl of Northumberland on his marriage to Dorothy Devereux the younger daughter of Walter Devereux, 1st Earl of Essex, who later received a grant of the freehold from King James I in 1604. It has remained in the possession of the Percy family, now the Dukedom of Northumberland, for over four hundred years. The Royalist army occupied the house during the Battle of Brentford in November 1642. Syon Park was rebuilt and landscaped by the Adam brothers and "Capability" Brown between 1766 and 1773. It became the new home of the Dukes of Northumberland when Northumberland House in the Strand was demolished in 1874.

Much of Isleworth became orchards in the 18th century (including part of Hugh Ronalds' renowned nursery), and then market gardens in the 19th century, supplying the London markets. Lower Square and Church Street still have buildings dating from the 18th and early 19th centuries. A striking element of this period was the establishment in Isleworth of many mansions and large houses, principally for aristocrats and high achievers. This phenomenon arose owing mainly to the collection of royal and noble residences and ecclesiastical establishments that already existed nearby. The subject is examined in depth in the "Notable houses" section.