It is believed that a fortified manor stood on the site, given to Geoffrey de Montbray, Bishop of Coutances, by William the Conqueror.

[2] In the Domesday Book it is referred to as a wealthy estate owned by the Bishop of Coutances, with a manor house, a great hall, and courtyards entered through gatehouses.

[3] The property passed through successive owners and at the end of the 14th century it was considerably expanded when Thomas De Lions, a nobleman originally from France, obtained a permit to enclose a park for his manor.

Sir John also asked the famous landscape designer Humphry Repton for advice about the east front of the house.

In about 1940 she was interviewed by Raymond Gorges, who was researching a book, and she gave him an engraving of the house showing the additions that she said were made by Sir John.

[11] His importance as a major builder of Ashton Court is verified by John Evans who in 1828 wrote a book about Bristol and its surrounding area.

It has of late been much enlarged with stables nearly as extensive as the house and also a park enclosed by a wall which is twelve feet high in the lowest part.

This part has been raised considerably and in a great measure rebuilt and is surmounted by two octagonal towers which rise to a height of 72 ft.

He converted the stables in the south east wing to living areas which included a huge museum for his natural history collection.

In the west wing he built a massive carved oak staircase with twist bannisters and introduced perpendicular windows.

The following description of this elaborate room with a waterfall fountain is given in this newspaper article as follows: This leads through two arched entrances to one of the most charming winter gardens of which any private mansion in the western counties can boast.

Round the tessellated flooring have been formed the gracefully curved flower borders edged with glazed tiling surmounted with rockery.

From the roof hang clusters of incandescent laps, interspersed with baskets filled with gracefully drooping ferns and from the surface of the water lilies modestly rise.

She also gave a few details of some interesting secret rooms and passages in the medieval part of the building on the western side which she referred to as "Drax's Kennel" and "The Fox's Hole".

Other records relating to the Ashton Court estate are also held by Wiltshire and Swindon History Centre[24] and the University of Bristol Special Collections.

[27] In order to create the long facade, the existing stables, to the right of the gatehouse, were converted to domestic use and given seven bays of Gothic mullioned windows.

[27] This classically designed wing has been attributed to Inigo Jones, but without supporting evidence;[27] as with a similar attribution at Brympton d'Evercy, also in Somerset, it seems to be based solely on the alternating segmental and pointed pediments over the groundfloor windows, and ignoring the irregularities in their spacings and placings, which Jones is unlikely to have countenanced.

[27] Overall, its length, contrasting styles, high gatehouse and lack of symmetry give the facade a collegiate rather than domestic appearance.

The focal point of the facade, the gatehouse, has multi-faceted turrets at its corners, In 1885, the gatehouse was given a Gothic makeover, which included raising its height and adding the fan vaulting to the ceiling of the passage leading, not to a great base court, as such grandiose architectural feature would suggest, but to a small glazed inner courtyard (the Winter Garden).

[27] The north wing was included in the remodelling work of 1805 and given ogee headed windows in the delicate Strawberry Hill Gothic style, popular at turn of the 19th century; it was a forerunner of the more medieval ecclesiastical Gothic style that was to characterise the architecture of the 19th century, and employed at Ashton Court during the 1885 alterations.

It was designed by Bauhaus architect Marcel Breuer as a show house for the Bristol furniture manufacturer Crofton Gane.

[23] Restoration has been an ongoing process since then, but even after extensive investment by both the council and from Heritage Lottery Fund grants, presently only about a quarter of the building is occupied or usable.

After problems were caused by a temporary move to Hengrove Park in 2001, due to the foot and mouth crisis, and a washout in 2007, the organisers declared bankruptcy in 2007.

[35] The lower lodge to Ashton Court and attached gates, railings and bollards, which were built in 1805 by Henry Wood, are Grade II* listed buildings.

[38][39][40] Since 2018, the mansion house has been managed by Bristol charity Artspace Lifespace, allowing the building to be open to the public for a variety of events.

The house stands within a large estate spanning the boundary between Bristol and North Somerset, approximately 2 kilometres (1.2 mi) from the city centre.

[44] Bristol's weekly parkrun event (a free, timed 5 km run organised by volunteers) is held at Ashton Court.

[47] Clarken Combe, at the western edge of the estate, is a woodland area with a range of plant species, including narrow-lipped helleborine, which grows here in small numbers under beech.