The Chinese artist and activist ranked second in 2015: That year, his country's authorities gave him back his passport. Ai has since been living in exile in Berlin. He made headlines in 2016 when Lego refused to provide bricks for one of his projects, fearing it would be too political, and due to various projects concerning refugees. He is shown here working on a film with refugees in Gaza.

As Britain faced its referendum on Brexit, the London-based German artist Wolfgang Tillmans officially turned activist with his pro-Remain print-it-yourself poster campaign (pictured). Among many other projects, the Turner Prize-winning photographer is now preparing a show for the Tate Modern in 2017. He also released his first music album this year.

The US art curator has been the director of the Whitney Museum of American Art since 2003. The institution moved into a $760-million (692-million-euro) new building in Manhattan, which opened in May 2015. In its first year, some 1.3 million people visited the "New Whitney," adding to the institution's established prestige.

The Munich-born, Berlin-based filmmaker and visual artist is also an essayist specialized in innovative media. This year, she took part in art shows worldwide, from biennials in Venice and Sao Paulo to contemporary art museums in LA and Madrid. She first appeared in the Power 100 in 2013 and has found her way into the top 10 within five years. Pictured is her work "Factory in the Sun."

The US gallerist runs 16 venues worldwide, and he's renowned for staging museum-quality shows. He represents top contemporary artists, from Jeff Koons to Anish Kapoor and Damien Hirst. Francis Bacon, Andy Warhol and Pablo Picasso are just a few of the big names featuring in his current exhibitions. Gagosian has steadily featured in "ArtReview's" top 10 since 2003.

Serota spent 30 years as the director the UK's Tate Museum and is now stepping down to become chair of England's Arts Council. Morris (pictured) succeeded Chris Dercon in January 2016 as the director of the Tate Modern, one of the four galleries of the influential art institution. She is the first woman to head the museum.

This German gallerist heads two spaces in New York, opened a gallery in London in 2012, and is set to inaugurate another huge one in Hong Kong in 2017. He also manages the careers of Isa Genzken, Wolfgang Tillmans, Jeff Koons, Yayoi Kusama, and Luc Tuymans - who all happen to feature on the "ArtReview's" prestigious list of 100 most influential people in the art world.

The Swiss couple runs major galleries in the world's art hubs: Zurich, New York, Los Angeles and Somerset in the southwest of England. These influential gallerists have introduced a museum-like approach to their shows, adding to their international popularity. They topped "ArtReview's" Power 100 list in 2015.

The Polish curator is the artistic director of Documenta 14. The major contemporary art show, which takes place every five years, will open in 2017 - this time in two cities, in Athens and Documenta's German hometown of Kassel. The upcoming event has boosted Szymczyk's influence in the art world, bringing him from rank 16 in 2015 to the second spot this year.

He heads London's Serpentine Galleries, but that's not what makes Obrist the most influential man in the art world. It's rather as the instigator of global, networked art projects that the Swiss museum director came to top the "ArtReview" list for the first time in 2009. Among others, his "Interview Project" collects thousands of filmed talks with the world's most significant artists and thinkers.