Paintings by numbers

This red-haired young woman staring moodily out of a window had recently been centre stage in a major exhibition in Chicago before it set a world record price for the artist at Christie's, New York, on Tuesday. The identity of the successful bidder is not known.

Painted 1886-87 when the artist was about 23, the work had belonged to Chicago collectors and philanthropists Neison Harris, who died in 2001, and his wife Bette, who died this summer.

Toulouse-Lautrec had always liked redheads and his model for this work is Carmen Gaudin, described by the artist in a letter to his mother as having hair of gold. The work depicts one of Paris's many laundresses, who often also worked as prostitutes, in a world of glamour and tawdriness which was also depicted by Emile Zola's novels. It is an early work of the type for which Toulouse-Lautrec would become famous, transforming the sad and tatty details of everyday life into something rather beautiful.

Au Moulin de la Galette, by PIERRE AUGUSTE RENOIR, £44.5M, MAY 1990

The girl in the white dress is said to be Estelle, the sister of Renoir's model, Jeanne. Another of his models, Margot, is on the left, dancing with a Cuban painter, Cardenas. Several of the artist's friend are at the foreground table. A smaller version of a work of the same name at the Musee d'Orsay in Paris, the Moulin de la Galette, near the top of Montmartre, was a place of entertainment where Renoir delighted in observing Paris at play. There is also a sketch of the same subject in the Ordrupgard Museum near Copenhagen. Like the Portrait of Dr Gachet [opposite], this was bought at auction by Ryoei Saito, the Japanese businessman from John Hay Whitney, former US ambassador to Britain. Saito caused outrage in 1991 when he apparently suggested he wanted this work and the Dr Gachet portrait cremated with him when he died. It is understood to have been since resold privately by Sotheby's for $50m.

Garçon à la Pipe, by PABLO PICASSO, £58M, MAY 2004

Painted by Picasso in 1905 when he was 24 and in his so-called Rose Period, the portrait depicts a young Parisian working boy crowned with a garland of roses, holding a pipe. He is thought to have been a young boy known as "P'tit Louis" who inspired other works of the period.

It was sold last year by the philanthropic foundation of the late John Whitney, a former American ambassador to Britain, who had bought it in 1950 for $30,000. The buyer was anonymous but the high price provoked speculation that it could only be a handful of American billionaires such as Microsoft founder Bill Gates. The price reflected its good condition and its rarity. Picasso produced only about 15 paintings during his brief Rose Period, named after the lighter palette he was using. Picasso is one of the most expensive artists in the world with several works having made exceptional prices in recent years. As long as 1989 Les Noces de Pierrette made £28m at auction; in 1997, La Reve sold for £27.4m and five years ago Femme aux Bras Croises made £28m.

Massacre of the Innocents, by PETER PAUL RUBENS, £49.5M, JULY 2002

Painted between 1609 and 1611, after Rubens returned to his home town of Antwerp, Belgium, after formative years studying in Italy, this work is now regarded as a masterpiece.

But until four years ago, it had been lost to view for 200 years having been wrongly attributed to Jan van den Hoecke, a minor follower of Rubens. For a long time it was on loan to a monastery in Austria because its then owner loathed it. At the age of 89, she decided to sell and consulted experts at Sotheby's, London, who decided it was a Rubens.

It was bought at auction by David Thomson, chairman of the Thomson newspaper group, for his father, Lord Thomson of Fleet. He is lending it to the National Gallery, London, where it is currently in the Rubens exhibition, but the work will eventually go to the Art Gallery of Ontario.

The painting tells the brutal Biblical story of when King Herod ordered new-born boys to be killed to prevent one becoming the Messiah.

Portrait of Dr Gachet, by VINCENT VAN GOGH, £47.1M, MAY 1990

Dr Gachet was the Dutch artist's doctor in the last months of his life and a man whose competence in that role has been much questioned.

It is one of van Gogh's most famous paintings and the subject of one of the most intriguing disappearing acts in art history. When the hammer came down at Christie's in New York 15 years ago, it emerged that the painting's owner was Ryoei Saito, a major Japanese manufacturer, who locked it away. When Saito died in 1996, it was unclear who owned the work - his heirs, his company or his creditors. It was not the first time the work had disappeared. In the 1930s, when the Nazis condemned modern works as "degenerate", the portrait was confiscated from a Frankfurt gallery and sold to purchase some politically acceptable hunting tapestries. Today it is now believed to be in a private collection.

Other highly priced van Goghs include Irises, which sold for £28m in 1989, and Portrait de l'artiste sans barbe, which sold in 1998 for £37.1m.