Diego Rivera was a life long Marxist and member of the Mexican Communist Party and eventually turned to Social Realism as a way to express his ideas about the oppression of the poor in a country dominated by a contrasting politics and colours. (Image: Man at the Crossroads en.wikipedia.org)

People have been creating murals since women learnt how to draw on cave walls. It is now believed that the majority of the cave muralists were women as the men would be out hunting, fishing, fighting. Image: David Alfaro Siqueiros (widewalls.ch)