David Alfaro Siqueiros was a Mexican social realist painter, best known for his large public murals using the latest in equipment, materials and technique. Along with Diego Rivera and José Clemente Orozco, he was one of the most famous of the "Mexican muralists". He was a member of the Mexican Communist Party, and a Stalinist and supporter of the Soviet Union who led an unsuccessful attempt to assassinate Leon Trotsky in May 1940.