The history of art is a history of controversy. What we now consider classic often has roots in artists who broke the rules. When the impressionists first began showing their work, they did so in protest of the Paris salon system that rejected them. Now we look at the work of these famous fine artists and think of how serene it is — but it all began with a scandal.

The last hundred years saw many controversies where popular artists turned the world of art on its head. But not all controversies make lasting change. While any list of contemporary artists is essentially a list of people who break out of the accepted norms, we want to know who are the controversial artists who made art what it is today?

Below is a list of the six most controversial artists of the last one hundred years (or so) who changed art forever, including the moments that shocked the world.

1- Marcel Duchamp
(7/28/1887 — 10/2/1968)

Duchamp’s art defied and then defined the art world. He saw most art as “retinal art” (meant only to stimulate the eye), but he wanted to stimulate the mind.

Marcel Duchamp paintings began as cubist and futurist studies of people in movement. When he painted the famous staircase painting (Nude Descending a Staircase, No. 2) in 1912, he caused a scandal. He was asked to remove the painting but refused, later stealing it from the gallery and taking it home in a taxi.

Soon after, Duchamp presented “ready-mades” in galleries — found objects that he called art simply because he said showed them as art. The most famous of these is Fountain (1917), an everyday urinal that he signed “R. Mutt”. His confrontation with the self-importance of the artworld continues to irk people inside it to this day.

While his name is synonymous with dadaism, he kept it at arm’s length. So what did Marcel Duchamp contribute to the dada movement? He challenged the very idea of art and the artistic process.

2- Andres Serrano
(8/15/1950 — Present)

Photographer Andres Serrano is a famous artist provocateur, notable for using his own bodily fluids in his work. And a history of Andres Serrano’s work is a gradual increase of these techniques to depict sacred items inside the most profane of substances. As you might have guessed, Andres Serrano and the church have a difficult relationship, but he remains a lifelong Christian.

His biggest controversy came in 1987 in reaction to his work Piss Christ. The photograph depicts the figure of Christ on the cross submerged in the artist’s own urine. After it’s display, he received death threats and denunciations by members of the US Senate and, of course, the clergy.

If you’ve never heard of him before, chances are you’ve seen his work. His work Blood in Semen III (1990), which was used for the cover of Metallica’s album Load, while his piece Piss in Blood XXVI (1987) was used for the band’s next album Reload.

3- Marina Abramovic
(11/30/46 — Present)

Serbian artist Marina Abramovic is one of the most famous artists working today. Marina Abramovic’s art explores the body in space. Early in her career, Abramovic and her one time collaborator (and romantic partner) Ulay explored male and female energies. In a piece called Imponderabilia (1977), they both stood naked side by side in front of a doorway, where the public was asked to squeeze between them to pass through, having to choose which artist to face as they pass.

Ulay and Marina eventually broke off their personal and artistic bonds, leading to a massive performance piece called Lovers (1988). Each began on an opposite side of the Great Wall of China, Ulay at the Gobi Desert and Abramovic at the Yellow Sea. The walked 2500 km and met in the middle to say goodbye.

She is the subject of the 2012 documentary The Artist is Present, which follows her in the lead up to her performance of the same name at the Museum of Modern Art. There, she sat at a table and stared blankly for hours, inviting the public to sit across the table from her. Ulay made a surprise return during the opening night of the show.

4- Pablo Picasso
(10/25/1881 — 4/8/1973)

Pablo Picasso is one of the most well known artists of all time. His leadership at the forefront of cubism defines a variety of artforms today. Picasso paintings went through many phases, the most recognizable is his shift to cubism. To define cubism requires understanding Picasso’s cubism, as he and Georges Braque were the major leaders of the movement. By looking at a subject from multiple angles and then cutting these views up and reorganizing them in surprising, abstract ways, Picasso revolutionized the very idea of representation in art.

In 1937, he finished Guernica, a brutal depiction of the Nazi and Italian Fascist bombing of Guernica on behalf of the Spanish nationalists. The painting helped raise awareness of the Civil War in Spain and helped shift worldwide opinion against fascism — causing major controversy all along the way.

5- Yoko Ono
(2/18/33 — Present)

Yoko Ono is, unfortunately, mostly known for her relationship to John Lennon of the Beatles. While John Lennon and Yoko made art together, it is her legacy as a leader in the development of conceptual and performance art that earns her a place on this list.

One of her earliest works is controversial to this day. In 1964, Yoko Ono’s Cut Piece shook the art world. Ono wore her nicest dress on a stage, kneeling before a pair of scissors. Audience members were invited to join her on stage and cut off pieces of her clothing. Yoko Ono today remains a provocative artist, peace activist, and collaborator with young artists.

6- Tracey Emin
(7/3/1963 — Present)

Tracey Emin has done it all. From painting to sculpture, photography to neon text. She is partly known for her affiliation with Billy Childish. She helped coin the term stuckism when telling Childish that his work was “stuck” in the world of painting, but she has disavowed the stuckists since.

Continuing the revolution in art started by Duchamp, her most controversial work might be My Bed. In 1998, she displayed her actual bed — complete with bodily fluids staining the sheets, and on the floor beside it were such real-life items as: underwear with menstrual blood stains, condom wrappers, and trash. Emin claimed her bed had been in such a state for days due to her recent bout with suicidal depression. Despite the important message and raw honesty (or perhaps, in part, because of this), My Bed created an uproar that went beyond the artworld and broke into the mainstream conversation.

In a similarly controversial act of artistic honesty a year earlier, Emin made a tent for display and sewed into the fabric the names of all the people she’d had intercourse with. Everyone I Have Ever Slept With 1963–1995 was an iconic moment where sexual text, art, and autobiography were combined.