Dreweatts have been appointed to sell the contents of the property which was designed between 1791 and 1797 by esteemed Scottish architect James Playfair, who was championed for his innovative designs in the Neoclassical tradition.

Sir John Soane, who was also famed for his Neoclassical designs, assisted in the final phase of the build following Playfair's death in 1794.

Having been a spectacular home for residents such as Charles Gordon of Buthlaw and Cairness, who commissioned it to be built, Major Thomas Gordon, a friend of Lord Byron, to the Gordon family who sold the estate to the Countess of Southesk, in 1937 (granddaughter of Edward VII), the house fell into disrepair until 2001.

It is rare for such a collection to go to auction.

The new owners who were both knowledgeable, as well as passionate about collecting, embarked on the enormous task of restoring the house and grounds.

They carefully curated each interior with important art works, furniture, decoration, lighting and textiles, that would bring the house back to its former glory.

This included the library, designed as an Etruscan room, with its colours derived from ancient painted terracotta vases, to the Egyptian Room featuring hieroglyphic symbols, which was believed to be one of the earliest surviving rooms of its kind in the world.

The success of this exceptional restoration was marked by the winning of the Georgian Group Architectural Awards prize for the best Georgian country house in Britain in 2009.

a portrait of H.R.H. Prince Frederick Augustus, Duke of York.

The sensitive reconstruction of the house both inside and out and the painstaking research into the works that were to adorn each room, can be witnessed across the collection and it these works that present for sale.

Among a range of important paintings in the sale is a portrait of H.R.H. Prince Frederick Augustus, Duke of York (1763-182), who commissioned the work himself directly from the celebrated English portrait painter Sir Thomas Lawrence, P.R.A.

Sir Thomas Lawrence, was one of the most popular portraitists of his generation and was called on regularly to paint portraits of the Royal family in England and Europe, as well as further afield, with Popes and Tsars sitting for him.

The portrait in the sale is an informal image of the Duke of York, depicting him in private dress wearing the ‘Star of the Garter’ pinned on a black frock coat.

Dreweatts have been appointed to sell the contents of the property.

The work was exhibited at the Royal Academy in 1822 and the popular acclaim it received resulted in an engraving by George Thomas Doo. It carries an estimate of £40,000-£60,000.

Another important portrait in the sale is by Royal Academician Francis Cotes (1726-70), one of the most fashionable portrait painters in London during the third-quarter of the 18th century.

The portrait in the sale encapsulates Grace Colhoun née Parsons (1742-1803), the daughter of Edward Parson, a landowner in Little Parndon, Essex and British Monsterrat. The work carries an estimate of £60,000-£100,000.

An equally significant painting in the sale is a portrait of Charles Hamilton, 5th Earl of Haddington (1650-85), known as Lord Binning until he inherited his father’s titles in 1669. It carries an esitmated of £7000-£10,000.

Cairness House, one of Scotland's most important Neoclassical homes.

An oil portrait by the British artist William Etty (1787-1849), the only important British painter before the 20th century to have dedicated his career to painting the nude and semi-nude, is another exciting addition to the sale.

The painting in the sale portrays the highly successful actor and theatre manager William Charles Macready (1793-1873). It carries an estimated of £5000-£7000.

Elsewhere in the sale is a historical Flemish tapestry depicting the Coronation of Alexander the Great (356-323 BC).

The woven scene features architectural framework and stairs leading up to a kneeling figure awaiting his crowning, with armies bearing standards, and carries an estimate of £10,000-£15,000.

Among a selection of sculpture is a carved marble bust of the Anglo-Irish statesman, diplomat and politician Robert Stewart, 2nd Marquess of Londonderry (1769-1822), with an estimate of £8000-£12,000.

Joe Robinson, Head of House Sales and Private Collections at Dreweatts, said: “It is an honour to present such a special collection from one of the most important houses in the history of Neoclassicism in Scotland.

"It is rare for a collection to come to market that has been so thoughtfully curated, with such impressive academic vision and decorative flare.

"The sale offers a fascinating insight into the art of collecting and demonstrates the dedication to quality and provenance that the owners put into obtaining the works.”

The auction will take place alongside another sale titled A Historic Townhouse on Wimpole Street, London in the popular Dreweatts Town & Country series.

Contents of Scotland's most important Neoclassical home to go to auction