Short answers, pulled from the story.
Performance art is an artwork in which the artist is present in the work, witnessed live or through documentation. Its five basic elements are time, space, body, the presence of the artist, and the relation between the artist and the public.
Performance art emerged in 1916, parallel to dadaism and under the umbrella of conceptual art, led by Tristan Tzara. Theorists locate its origins at the beginning of the 20th century, alongside constructivism, Futurism and Dadaism, with the Cabaret Voltaire in Zurich, Switzerland as a key birthplace.
The main pioneers of performance art include Carolee Schneemann, Marina Abramovic, Ana Mendieta, Chris Burden, Hermann Nitsch, Joseph Beuys, Nam June Paik, Tehching Hsieh, Yves Klein and Vito Acconci. The term "performance art" became widely used in the 1970s.
Chris Burden became known in the 1970s for performances in which personal danger was the artistic expression. In Shoot in 1971 an assistant shot him in the arm, in Five Day Locker Piece in 1971 he was locked in a locker for five days, and in Bed Piece in 1972 he stayed in bed in a gallery for twenty two days.
In 1988, Marina Abramovic and Ulay walked the Great Wall of China from opposite ends to end their collective. Ulay started in the Gobi desert and Abramovic at the Yellow Sea, each walking 2,500 kilometres before meeting in the middle and saying goodbye.
Pussy Riot members were arrested after entering the Cathedral of Christ the Saviour in Moscow on the 21st of February 2012 to protest the re-election of Vladimir Putin with a song and dance. Maria Alyokhina and Nadezhda Tolokonnikova were arrested on the 3rd of March 2012 and accused of vandalism, and Amnesty International considers the members prisoners of conscience.