Aristocrats sell off their heirlooms to keep the wolves from the door

The aristocratic owners of some of Britain's most famous country estates have sold off art treasures worth £100m since the start of the recession. Many are heirlooms and are being sold at auction – often to foreign bidders – to pay for the renovation and upkeep of country homes. Cuts in government spending have raised concerns that treasure with heritage value will increasing be sold abroad as museums and galleries are unable to afford them. All these artworks come from stately homes, most of which are open to the public. Around £80m worth of major works have been sold in this way, while additional, smaller works are being marketed discreetly, an investigation by The Art Newspaper claims.

Artworks, furniture and porcelain from Earl Spencer's mansion at Althorp were sold at Christie's last week for £21.1m. The Trustees of Althorp Estate said they had chosen to sell the selection of works "while maintaining the breadth and integrity of the core Spencer collections".

Andrew Waters of Christie's noted that this was part of a collection amassed over hundreds of years by the Spencer family, making it one of the finest in Britain.

The sale caught the interest of collectors and institutions from around the world, clearly visible from the heavy volume of people that visited the London salerooms to view the pre-sale exhibitions.

Meanwhile, a descendant of the fifth Earl of Rosebery made headlines last week by selling a Turner painting at Sotheby's for £29.7m – a new auction record for the painter. It was originally bought by the aristocratic family in 1878. Many experts regard Modern Rome – Campo Vaccino as the most important Turner oil painting in private hands. Alexander Bell, co-chair of old master paintings at Sotheby's, said participation in last week's old master sales from private collectors – from all over Europe, Russia and North America – was "notably higher than usual and buyers came from some 25 different countries".

A £10m bronze relief by Pierino da Vinci, which is part of the collection on public view at Chatsworth House in Derbyshire, was recently bought by the Prince of Lichtenstein, most probably for his museum in Vienna. The sculpture, 'Ungolino Imprisoned with his Sons and Grandsons', entered the Duke of Devonshire's collection in 1794 and had been on public display since 1833. The Chatsworth House Trust said the sale, while unfortunate, would "allow for responsible, long term estate planning".

A smaller heirloom, a silver wine cistern made for Thomas Wentworth and passed down to the present day Marquis of Lothian in Southern Scotland, was also sold last week.

Stephen Deuchar, director of the charity The Art Fund, believed the slew of sales from country homes was caused by a "combination of a different economic climate for owners plus a buoyant art market at the top end, an unusual combination."

However there was one encouraging sign in May when the National Gallery was able to find a purchaser for Domenichino's St John the Evangelist which Sir George Christie of Glyndebourne had previously been sold to a foreign buyer at auction for £9.2m. When an export license was deferred a UK buyer stepped in.

Going, going, gone: national treasures worth £100m

*Earl of Rosebery

JMW Turner's masterpiece Modern Rome: Campo Vaccino was sold at Sotheby's last week for £29.7m, an auction record for the artist. The painting was sold by a descendent of the 5th Earl of Rosebery, who acquired it in 1878, to the J Paul Getty Museum in Los Angeles. For the past 22 years, Modern Rome has been on long-term loan to the National Galleries of Scotland

*Marquis of Lothian

The Marquis of Lothian sold a giant silver wine cooler once belonging to Thomas Wentworth, 3rd Baron Raby, at auction last week for £2.5m. The Great Silver Wine Cistern, which weighs around 75kg and measures 1.3m across, has been described as being as "large as a small bathing tub". The piece sold at Sotheby's to a private Asian buyer, supposedly setting a new record price for English Silver.

*Earl Spencer

Christie's auctioned a number of items from the Spencer estate last week, with a painting by Sir Peter Paul Rubens achieving over £9m. A Commander Being Armed for Battle went to an anonymous bidder at Sotheby's, the second-highest price a Rubens painting has achieved at auction. Other lots included Il Guercino's painting King David, pictured left, which achieved almost £5.2m, and a selection of George II furniture.

*Earl of Jersey

The Earl of Jersey sold Sir Anthony van Dyck's Self Portrait in December for a record £8.3m, smashing pre-auction estimates of £2-3m. The winning bidder at the Sotheby's action was TV's Antiques Roadshow fine art expert Philip Mould, in partnership with US-based art dealer Alfred Bader. Before the sale, the Self Portait had been in the Earl's family for almost 300 years.