Muralism

n. artistic movement of large-scale narrative murals

A mural is a painting on a wall, ceiling, or other large permanent surface.Murals of sorts date to prehistoric times such as the paintings on the Caves of Lascaux in southern France, but the term became famous with the Mexican "muralista" art movement (Diego Rivera, David Siqueiros, or José Orozco). There are many techniques. The best-known is probably fresco, which uses water soluble paints with a damp lime wash, a rapid use of the resulting mixture over a large surface, and often in parts (but with a sense of the whole). The colors lighten when dried.
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1930 term for wall paintings - art movement influenced from muralismo favoring decorative subjects - compare street art and graffiti 

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