The three-day sale will showcase items belonging to the Devonshire family of Chatsworth estate, including Georgiana, the infamous fifth Duchess of Devonshire, and the current Dowager Duchess who is the youngest of the notorious Mitford sisters.

The hidden treasures, which date from the 16th century. will be displayed at Chatsworth on October 1-4 before the auction on October 5-7.

Many rare architectural fixtures and fittings such as fireplaces and door frames, room furniture including chairs, cupboards and lamps will be included to give a unique glimpse into the lives of family members.

Some 20,000 objects in around 1,400 lots are estimated in value from £20 to £200,000 and are expected to raise around £2.5m.

Entry to the pre-sale exhibition will be by catalogue, on sale at Chatsworth or Sotheby's from September onwards.

The Duke of Devonshire said: "It's been fascinating to sort through the attics, revisiting my family's history and seeing long hidden treasures from Devonshire House and elsewhere.

"When we moved in to Chatsworth several years ago we realised that we were very short of space, so the auction will mean we can reorganise to improve the displays and storage."

"There are some very impressive objects and the good news is that their sale means many of them will go back on display for the first time in decades.

"The proceeds will be used to further some projects both at Chatsworth and on our other Estates, which we are delighted that this sale of items will accelerate.

"Everybody here works very hard to make Chatsworth more enjoyable and interesting and that has paid off with visitor numbers rising for the past few years, more than 10% this year alone."


History of the Devonshire family

Georgiana, 5th Duchess of Devonshire

The legendary Duchess was the leading light of London life, the undisputed queen of fashion and centre of the so-called 'ton' (a high society clan of the most illustrious people in the country), who was painted by Gainsborough, Reynolds and Cosway.

A compulsive gambler, the beautiful Duchess used her considerable charm to placate her creditors, whilst borrowing from the Prince of Wales amongst others to fund her habit and purchase the latest fashions in clothes and furniture.

A staunch Whig supporter and influential political activist, today she is perhaps more famous for her ménage-à-trois with Lady Elizabeth (Bess) Forster and the 5th Duke.

Having gambled herself deep into debt, Georgiana fell foul of her husband's agent, John Heaton, for commissioning a considerable amount of François Hervé furniture, including a pair of simulated rosewood and caned settees, circa 1780, (est. £8,000-12,000).

Items that Georgiana chose herself for her personal rooms feature in the sale, such as a set of eleven George III painted and caned chairs, almost identical to those used by Keira Knightley – in the film of Georgiana's extraordinary life 'The Duchess' (est. £2,000-3,000).



'Debo', The Dowager Duchess of Devonshire

Deborah is known not only for being the youngest of the extraordinary Mitford sisters, but as the Duchess who ensured the survival of the estate into modern times, in an era when many of the eminent family houses of Britain faced closure.

A patron of artists at the forefront of the contemporary art scene, such as Lucian Freud, as well as being close friends with the likes of Alan Bennett and Cecil Beaton, her personal mementos in the sale range from a walnut-veneered combined record 'changer' and wireless by Garrard & Co to personal jewels, tapestry and ceramics.



The Bachelor (6th) Duke

The Duke transformed the Devonshire Estate, building a new wing at Chatsworth to house his extensive collections.

He was a close friend of Tsar Nicholas I, attending his coronation in his capacity as Ambassador Extraordinary from the Court of St James to the Russian Empire.

During his time in St Petersburg the Duke purchased a wrought iron, wood and leather upholstered Russian sleigh in which he liked to drive through the snowy streets of the capital (est. £2,000-3,000).

The Duke employed the Royal decorators J. G. Crace to refurbish, among others, Chatsworth and Devonshire House, creating two of the most sumptuously decorated homes in the country – every empty space was gilt and embellished with elaborate mouldings, bare walls were hung with vast mirrors and the rooms adorned with rich silks and textiles.

A set of six Louis XV carved giltwood fauteuils, from the mid-18th century, covered in original blue and gold silk lampas are part of the luxurious Crace refurbishment (est. £18,000- 25,000).