Ai Weiwei, the Chinese artist and activist who was imprisoned for 81 days earlier this year, topped ArtReview’s annual ranking of the 100 most influential people in the art world, the Power 100, published today.

The Beijing-based artist -- who last year paved Tate Modern’s monumental Turbine Hall with 100 million porcelain sunflower seeds -- “was ranked number one as a result of his activism as much as his art practice,” London-based ArtReview said in an e-mailed release, noting that artists no longer worked in “a privileged zone” defined by galleries or museums.

Every year, timed to coincide with London’s Frieze Art Fair, Art Review gathers an international panel of art-world professionals to pick the 100 most influential people in their field. Last year’s Power 100 topper, international art dealer Larry Gagosian, ranked fourth this year.