Mayor of London Sadiq Khan (L) and Nicholas Serota, director of the Tate art museums and galleries visit a new viewing platform during the unveiling of the New Tate Modern in London, Britain, June 14, 2016. REUTERS/Stefan Wermuth 

Tate Director Nicholas Serota (L), Britain's Minister for Culture, Media and Sport Maria Miller (C) and Hyundai Motor Vice Chairman Euisun Chung pose during a photo call at Tate Modern in London January 20, 2014. Today, Tate announced the formation of a new eleven year partnership with Hyundai Motors. REUTERS/Suzanne Plunkett (BRITAIN - Tags: ENTERTAINMENT SOCIETY) 

Architect Adam Caruso (L), Director of Tate Britain Penelope Curtis (2nd L), Architect Peter St John (3rd L), John Browne Chairman of the Tate (4th L), and Nicholas Serota Director of the Tate (FRONT R), pose with artists above the new spiral staircase at Tate Britain in central London November 18, 2013. The 45 million pounds ($72.4 million) transformation of the building was unveiled to the media on Monday. REUTERS/Olivia Harris (BRITAIN - Tags: ENTERTAINMENT SOCIETY) 

The Director of Tate, Nicholas Serota, poses for photographers on an extension to Tate Modern which in the process of being built, in London April 12, 2013. The new development project will increase Tate Modern's size by 60% adding 21,000 square meters of new space, Tate announced at a media event to reveal details of funding. REUTERS/Suzanne Plunkett (BRITAIN - Tags: ENTERTAINMENT SOCIETY) 

The Director of Tate, Nicholas Serota, poses for photographers on an extension to Tate Modern which in the process of being built, in London April 12, 2013. The new development project will increase Tate Modern's size by 60% adding 21,000 square meters of new space, Tate announced at a media event to reveal details of funding. REUTERS/Suzanne Plunkett (BRITAIN - Tags: ENTERTAINMENT SOCIETY) 

Director Nicholas Serota speaks of the new extension being built (pictured) during a news conference at the official opening of The Tanks, new galleries within the Tate Modern art gallery in London July 16, 2012. REUTERS/Luke MacGregor (BRITAIN - Tags: ENTERTAINMENT) 

Director Nicholas Serota poses at the official opening of The Tanks, new galleries within the Tate Modern art gallery in London July 16, 2012. REUTERS/Luke MacGregor (BRITAIN - Tags: ENTERTAINMENT) 

Director Nicholas Serota and architect Jacques Herzog (R) pose at the official opening of The Tanks, new galleries within the Tate Modern art gallery in London July 16, 2012. REUTERS/Luke MacGregor (BRITAIN - Tags: ENTERTAINMENT) 

Tate Director Nicholas Serota speaks during a news conference at the Foundling Museum in London April 13, 2011. The Art Fund announced today that it will increase funding by 50 percent to help museums and galleries buy and show art. REUTERS/Suzanne Plunkett (BRITAIN - Tags: ENTERTAINMENT SOCIETY) 

Tate Director Nicholas Serota speaks during a news conference at the Foundling Museum in London April 13, 2011. The Art Fund announced today that it will increase funding by 50 percent to help museums and galleries buy and show art. REUTERS/Suzanne Plunkett (BRITAIN - Tags: ENTERTAINMENT SOCIETY) 

Tate Britain gallery director Nicholas Serota speaks during the launch of the Google's Art Project website in London February 1, 2011. Google aims to bring the world's great art galleries into the home with a new website that offers virtual tours, the ability to build a private collection of masterpieces and ultra-high resolution images. REUTERS/Stefan Wermuth (BRITAIN - Tags: ENTERTAINMENT SCI TECH BUSINESS) 

Nicholas Serota, Director of Tate, speaks at a news conference on Turner's "The Blue Rigi" (R), in London March 1, 2007. A Turner watercolour sold at auction last year for 5.8 million pounds ($11 million) and destined to be taken overseas will now remain on public view in Britain after a high profile campaign to block its export. REUTERS/Luke MacGregor (BRITAIN) 

Nicholas Serota, Director of Tate, speaks at a news conference on Turner's "The Blue Rigi", in London March 1, 2007. A Turner watercolour sold at auction last year for 5.8 million pounds ($11 million) and destined to be taken overseas will now remain on public view in Britain after a high profile campaign to block its export. REUTERS/Luke MacGregor (BRITAIN) 

Britain's Nicholas Serota, Director of the Tate, stands in front of Andy Warhol's 'Marilyn Diptych' at the Tate Modern gallery in central London on May 22, 2006. The gallery has re-hung some of its permanent collection for the first time since its 2000 opening, organised around key periods in twentieth century art history. 

Britain's Nicholas Serota, Director of the Tate, stands in front of Andy Warhol's 'Marilyn Diptych' at the Tate Modern gallery in central London on May 22, 2006. The gallery has re-hung some of its permanent collection for the first time since its 2000 opening, organised around key periods in twentieth century art history. REUTERS/Toby Melville 

Britain's Nicholas Serota, Director of the Tate, stands in front of Andy Warhol's 'Marilyn Diptych' at the Tate Modern gallery in central London on May 22, 2006. The gallery has re-hung some of its permanent collection for the first time since its 2000 opening, organised around key periods in twentieth century art history. REUTERS/Toby Melville 

Britain's Nicholas Serota, Director of the Tate, stands in front of Andy Warhol's 'Marilyn Diptych' at the Tate Modern gallery in central London on May 22, 2006. The gallery has re-hung some of its permanent collection for the first time since its 2000 opening, organised around key periods in twentieth century art history. REUTERS/Toby Melville 

British artist Simon Starling (L) is congratulated by Tate Director Nicholas Serota after winning the Turner Prize at the Tate Britain gallery in London December 5, 2005. Starling won the prestigious arts prize worth 25,000 pounds sterling ($43,370). REUTERS/Dylan Martinez 

Sir Nicholas Serota, director of London's Tate Gallery points to a Wild West-style Wanted poster as he poses for photographers with a portrait of the late British artist Francis Bacon in Berlin June 22, 2001, designed by Lucian Freund. The Tate Gallery is the owner of the painting. Berliners will wake on Friday to find their city plastered with 2,500 Wild West-style Wanted posters offering a reward of 300,000 deutsche marks ($13,000) for the return of a pocket-sized painting stolen 13 years ago painted by Lucian Freud.

FAB 

Sir Nicholas Serota, the director of London's Tate Gallery poses for photographers in front of a Wild West-style Wanted poster with a portrait of the late British artist Francis Bacon in Berlin June 22, 2001, designed by Lucian Freund. The Tate Gallery is the owner of the painting. Berliners will wake on Friday to find their city plastered with 2,500 Wild West-style Wanted posters offering a reward of 300,000 deutsche marks ($13,000) for the return of a pocket-sized painting stolen 13 years ago painted by Lucian Freud.

FAB 

Newly appointed Director of the Gallery of Modern Art Lars Nittve (L) and Director of the Tate Gallery Nicholas Serota chat on the top floor of the Tate Gallery of Modern Art during the toping out ceremony September 16. The new gallery, constructed over a six year development programme will transform an old power station into London's landmark millennium project.

IW/ME 

Newly appointed Director of the Gallery of Modern Art Lars Nittve (L) and Director of the Tate Gallery Nicholas Serota chat on the top floor of the Tate Gallery of Modern Art during the toping out ceremony September 16. The new gallery, constructed over a six year development programme will transform an old power station into London's landmark millennium project.

IW/ME