Actionism was a short-lived movement in 20th century art that focused on "action art" and can be divided into two groups. The first group, Action and Painting, emphasized the physical action involved in the painting process and was exemplified by artists like Pollock, de Koonig, Kline, and Guston. The second group took a more extreme approach through performances involving violence, destruction, and shock value. Key artists associated with Actionism included Hermann Nitsch, Otto Muehl, and Günter Brus, though the movement was brief and controversial.