Built by Thomas Wyndham to the designs of Roger Morris, it is the earliest Georgian Gothic Revival castle in England predating better-known examples such as Strawberry Hill House by over twenty years.

A home of the Wyndham family for some 150 years, the first half of the twentieth century saw a disastrous fire, and subsequent asset-stripping, which brought the castle close to ruination.

Slowly restored from 1954, in the 1970s the castle housed a recording studio used by, among other major bands, Black Sabbath, Led Zeppelin, Deep Purple, Bad Company, Queen and Sweet.

[3] Alistair Rowan suggests that construction was undertaken in two phases, the main frontage in the first building period of 1727–1728, and the rear of the house, with the library on the ground floor and bedrooms above, after his second marriage in the 1730s.

On the deaths of their fathers, in 1814 and 1824 respectively, they inherited considerable estates in Gloucestershire, Norfolk and South Wales, with Quin also succeeding to the Earldom of Dunraven and Mount-Earl.

[7] The first half of the 20th century saw the castle suffer a serious fire in 1930, and after the Second World War, the loss of its floors, roofs and many of its internal fittings and decorations prior to intended demolition.

Many major rock bands including Led Zeppelin, Deep Purple, Mott the Hoople,[8] Black Sabbath,[9] Bad Company, Queen and Whitesnake recorded at the castle.

[b][2] Alan Brooks, in the revised 2002 Gloucestershire Pevsner, goes further, calling Clearwell, "the earliest Gothick Revival castle in England".

[3] Little of the original interior has survived; Victorian remodelling in the mid-19th century and the fire and subsequent gutting of the building in the mid-20th, destroyed most of the decoration.