However, after that date the acquisition through marriage of the Blakiston estate of Gibside gave the Bowes family an even greater influence in the north of the county and a share in the immense wealth that was to be acquired from the coal trade.

[8] After the split inheritance dispute following the death of John Bowes, 10th Earl of Strathmore and Kinghorne, in 1820, it belonged to his legitimated son John Bowes until his death in 1885 (he is buried in the Gibside chapel), when under the entail it reverted to his cousin Claude Bowes-Lyon, 13th Earl of Strathmore and Kinghorne.

Sir George Bowes died in September 1760, and the shell of the building was completed in 1769 under the supervision of his widow, Mary Gilbert.

His grandson John Bowes, 10th Earl of Strathmore and Kinghorne, completed the interior work and had the chapel consecrated in 1812.

They consist of a holy table surrounded by rails; a triple-decker pulpit, the sounding board supported by a single Ionic column; and box pews in the corners and side apses, the latter curved to fit the space.

[13] The orangery was built between 1772 and 1774 for Mary Eleanor Bowes, who had a keen interest in botany, to a design by William Newton.

The rear contains five sash windows, the middle three forming a canted bay with views across the Derwent valley.

The building, which originally had a slate roof, was converted into a conservatory by John Bowes in 1885 by the addition of a glazed iron roof; at the same time a brick podium was constructed in the centre of the main room to display plants and a heating system added, with a boiler installed in the western lobby.

The roof was removed between the First and Second World Wars, since when the orangery has been a roofless shell, however the fabric was consolidated by the National Trust in 2005.

The east wing, which contained the visitor entrance and which faced the new coach drive created for Sir George, is decorated in the Palladian style.

Inside, some plasterwork and the stalls of the show stable survive, the latter separated by narrow wooden classical columns.

What remains is protected by Grade II* listed building status[16] and included in the Heritage at Risk Register.

[17] Parts of the grounds have been designated a Site of Special Scientific Interest, including a forest garden.