D'Ivry's holding became part of the honour of St. Valery, which in the 13th century was owned by Richard, 1st Earl of Cornwall.

The royal estate at Hampton Gay became part of the honour of Gloucester and thereby followed the same descent as the manor of Finmere.

[7] In about 1170 Reginald de Gay gave a virgate of land (about 30 acres (12 ha)) to the house of the Knights Templar at Cowley, Oxfordshire.

In about 1311 the Templars were suppressed and their holding at Hampton Gay was transferred to the Knights Hospitaller of Saint John of Jerusalem.

In about 1218 Robert de Gay gave the tenancy of half a hide of the St. Valery estate to the Benedictine convent at Godstow.

Wenman died in 1690 and his widow sold Hampton Gay in 1691 to William Hindes of Priors Marston in Warwickshire.

On his death in 1943 Col. Barry left the estate to his daughter Jeanne and her husband, the Honourable James McDonnell.

Early in the 21st century English Heritage placed the manor house ruins on its register of historic buildings at risk, listing its priority as "A" and its condition as "very bad".

F. C. Hingeston, altered the church to his own designs, replacing its round-headed Georgian windows with ones in an Early English Gothic style and having the south doorway re-cut in a Norman revival fashion.

The most notable is a 17th-century wall monument with kneeling effigies of Vincent and Anne Barry and their daughter Lady Katherine Fenner.

In 1880 it had both a water wheel powered by the river and a steam engine fed by a Cornish boiler, and could produce about a ton of paper per day.

John Barry, who bought the manor in 1544, had made his money from wool, and he or his heirs enclosed land at Hampton Gay for sheep pasture.

Led by Bartholemew Steer who farmed the land at Hampton Gay, the rebels planned to murder landowners including Vincent Barry and his daughter and then to march on London.

A carpenter at Hampton Gay warned Barry, five ringleaders were arrested and taken to London for trial, Bartholemew Steer, who was recognised as the leader was sentenced to be hanged drawn and quartered.

It was established in 2003 and has been a pioneer of tayib (natural) farming based on principles of traditional regenerative agriculture, combining environmental and social sustainability.