Tracey Emin's controversial My Bed artwork, owned by Charles Saatchi, has been sold for £2,546,500 at an auction at Christie's in London.
The Margate-born artist was in the packed auction room to see My Bed fetch a record amount for her work.
The auction house was unable to immediately reveal the buyer.
The artwork, which made the 1999 Turner Prize shortlist, went up for sale with a guide price of between £800,000 and £1.2 million.
Saatchi, who paid £150,000 for the work in 2000, sold it to support the work of the Saatchi Gallery Foundation.
Creations by Tracey Emin and Grayson Perry will appear among more than 100 contemporary artworks to go on show at Buckingham Palace.
The exhibition will mark the Queen's Diamond jubilee last year, and also features works from David Hockney and Anish Kapoor.
The works were loaned by the Royal Academy and include creations from some of its most high-profile artists.
Mr Hockney's work is a colourful image of the Queen's initials from her cypher "EIIR" created on an iPad, while Emin submitted a monoprint portrait of the monarch titled HRH Royal Britannia.
Artist Tracey Emin, whose journey from controversy to respectability has been marked with a CBE, said receiving the honour felt like being "pushed in at the deep end".
The 49-year-old, who grew up in Margate, Kent, is perhaps best known for her work My Bed, which featured an unmade bed littered with condoms, cigarette packets and a pair of knickers.
Asked about her award of the CBE, she said: "I think they pushed me in at the deep end. But I'm absolutely thrilled. It's been insane trying to keep it a secret but I'm really looking forward to seeing the look on my mum's face.
"For me this honour is a symbol of how art can change people's perception of life and view the world in a different way."