Francis Bacon, Turning Figure, 1963, Estimate £6-8 million at this season's...

• People: Francis Bacon, Turning Figure, 1963, Estimate £6-8...

Damien Hirst, Compassion, Estimate £600,00-800,000 at this season's Contemp...

• People: Damien Hirst, Compassion, Estimate £600, 00-800, 0...

Grayson Perry, Love Letters, 1994, Estimate £80,000-120,000 at this season'...

• People: Grayson Perry, Love Letters, 1994, Estimate £80, 0...

Maurizio Cattelan, Untitled, Estimate £600,000-800,000 at this season's Con...

• People: Maurizio Cattelan, Untitled, Estimate £600, 000-80...

George Condo, Seated Nude, Estimate £400,000-600,000 at this season's Conte...

• People: George Condo, Seated Nude, Estimate £400, 000-600,...

Jean Dubuffet, Episode Champetre, 1974, Estimate £900,000-1,200,000 at this...

• People: Jean Dubuffet, Episode Champetre, 1974, Estimate £...

Gerhard Richter, Ziege (Goat), Estimate £6-8 million at this season's Conte...

• People: Gerhard Richter, Ziege (Goat), Estimate £6-8 milli...

Grayson Perry, Love Letters, 1994, Estimate £80,000-120,000 at this season'...

• People: Grayson Perry, Love Letters, 1994, Estimate £80, 0...

Francis Bacon, Turning Figure, 1963, Estimate £6-8 million at this season's...

• People: Francis Bacon, Turning Figure, 1963, Estimate £6-8...

Francis Bacon, Turning Figure, 1963, Estimate £6-8 million at this season's...

• People: Francis Bacon, Turning Figure, 1963, Estimate £6-8...

David Hockney, The Splash, 1966, set to make waves at Sothebys with an Esti...

• People: David Hockney, The Splash, 1966, Estimate £20-30m

David Hockney, The Splash, 1966, set to make waves at Sothebys with an Esti...

• People: David Hockney, The Splash, 1966, Estimate £20-30m

KAWS, AT THIS TIME, 2013, Estimate £700,000-900,000 at this season's Contem...

• People: KAWS, AT THIS TIME, 2013, Estimate £700, 000-900, ...

KAWS, AT THIS TIME, 2013, Estimate £700,000-900,000 at this season's Contem...

• People: KAWS, AT THIS TIME, 2013, Estimate £700, 000-900, ...

Yves Klein, Untitled Anthropometry (ANT 132), 1960, Estimate £6-8 million a...

• People: Yves Klein, Untitled Anthropometry (ANT 132), 1960...

Jean-Michel Basquiat, Rubber, 1985, Estimate £6-8 million at this season's ...

• People: Jean-Michel Basquiat, Rubber, 1985, Estimate £6-8 ...

Jean-Michel Basquiat, Rubber, 1985, Estimate £6-8 million at this season's ...

• People: Jean-Michel Basquiat, Rubber, 1985, Estimate £6-8 ...

David Hockney, The Splash, 1966, set to make waves at Sothebys with an Esti...

• People: David Hockney, The Splash, 1966, Estimate £20-30m

David Hockney, The Splash, 1966, set to make waves at Sothebys with an Esti...

• People: David Hockney, The Splash, 1966, Estimate £20-30m

David Hockney, The Splash, 1966, set to make waves at Sothebys with an Esti...

• People: David Hockney, The Splash, 1966, Estimate £20-30m

David Hockney, The Splash, 1966, set to make waves at Sotheby’s with an Est...

• People: David Hockney, The Splash, 1966, Estimate £20-30m

David Hockney, The Splash, 1966, set to make waves at Sothebys with an Esti...

• People: David Hockney, The Splash, 1966, Estimate £20-30m