MURAL is one of the oldest forms of artistic expression, includes all painting executed for the express purpose of embellishing or decorating a wall. The word mural is derived from the Latin murus ("wall").

A variety of techniques can be subsumed under the general heading of mural painting. The term fresco sometimes incorrectly used interchangeably with mural, refers to only one technique of mural painting. In true fresco, or buon fresco, pigment is applied to wet plaster, so that the paint actually becomes part of the wall. In fresco secco, or dry fresco, the artist applies pigment to a specially prepared wall whose surface has first been allowed to dry. Other techniques of mural painting include encaustic; painting on canvas, which is then affixed to a wall; painting in various pigments directly on the surface of the wall; mosaic; stained glass; baked enamel; modern synthetic materials; and photographic murals.

The murals at the Villa of the Mysteries near Pompeii depict religious initiation rites invoking the god Dionysus.

Leonardo da Vinci created "The Last Supper"( 1495-98) for the convent refectory of Milan's Santa Maria delle Grazie. He use a new technique of oil and tempera painted on a mastic-and-pitch base covering the stone wall.

History:

The earliest known mural art is the paintings discovered in Chauvel Cave in France in 1994; these are estimated to be 31,000 years old. Like the later cave paintings at Altamira, Spain (1879), and Lascaux, France (1940), animals are depicted in yellow, red, black, and brown earth pigments.

Beginning in the 3d millennium BC, Egyptian artist decorated the wall of tombs with formal scenes of warfare, hunting and ceremonies. Fresco was first used (c.1700 BC) in the lively work of Minoan Art Crete, Although little remains of these early efforts. Largely vanished also are the epic murals of classical Greece (6th-5th centuries BC), to which Greek literature often refers. Most direct knowledge of Greek wall painting comes from the sophisticated and action filled mosaics of the Hellenistic period, on which the Olynthos mosaics (c.400 BC) are the prime example. Roman artists adopted and developed the art of mosaic, and they filled the walls of homes and temples with naturalistic wall paintings such as those preserved at Pompeii and Herculaneum Pompeiian paintings reflect the great range and expertise of classical muralist, who were adept at depicting illusionistic  trompe-l'œil  architectural settings and realistic landscapes, animals and portraits.

From approximately the 4th through the 13th centuries mosaics dominated European mural decoration, reaching an unsurpassed peak of richness and color in Early Christian Art and, especially, Byzatine art. The notable centers of mosaic production were Ravenna, Italy, and Constantinople (now Istanbul), where Byzatine artist perfected a stately, hieratical, and two-dimensional style that influenced almost all forms of pictorial expression in medieval Europe.

The dethronement of mosaic as the preeminent medium of European mural art occurred in 14th-century Italy, where fresco was reborn in the Genius of Giotto and Simone Martini. In Giotto's Arena Chapel frescoes (c.1305, Padua) the pictorial depth and narrative interest of classical art returned to mural painting, banishing the static flatness of mosaic art. Giotto's revolution in mural art was carried on and broadened by the great painters of the Early Renaissance period (c.1420-1500), the most notable of whom were Fra Angelico, Masaccio and Piero della Francesca. The high point of Renaissance fresco and one of the greatest expressions of mural art came in brief span of 20 years (1495-1515) , with the unparalleled freedom and beauty of Leonado da Vinci's "The Last Supper" (1495-98; Santa Maria delle Grazie, Milan); Raphael Sanzio's "School of Athnens"(1510-11; Stanza della Segbatura, Vatican) and Michelangelo's Sistine Chapel ceiling (1508-12). Throughout the remainder of the 16th century, Italian Late Renaissance and Mannerist painters such as Paolo Veronese and Giulio Romano experimented with illusionistic trompe-l'œil ceiling and wall frescoes that emphasize technical virtuosity.

During the baroque period of the 17th century, fresco gave way to panel painting in mural art, and dramatic, exuberant wall decorations such as Peter Paul Ruben's Marie de Medici cycle (1622-25; Louvre, Paris) filled the palaces and villas of northern Europe. The kinetic drama of baroque wall painting was followed by the bold romanticism of Eugène Delacroix's murals for Saint Sulpice (1856-61) and the Louvre (1859-51) in Paris.

Mural painting generally declined in importance during the 19th century, although neo-Gothic movements such as the English Pre-Raphaelites and the German Nazarenes resurrected some of medieval mural art. Modern interest in this ancient art form was rekindled, however, the murals executed in the 1890s for the 1893 Chicago World's Fair by Mary Cassatt, Kenyon Cox and others the Boston Public Library by Pierre Puvis de Chavannes, John Singer Sargent, Library by Pierre Puvis de Chavannes, John Singer Sargent and others. These public works led directly to the three major movements that have dominated 20th-century mural painting: the muralist of 1920's and 30's, the American muralist of the 1930's and early 40's, and the outdoor-urban muralist of the contemporary era.

The Mexican muralist, especially Diego Rivera, José Clemente Orozco and David Alfaro Siqueiros, used fresco and other mural techniques to express revolutionary themes. Rivera's work in the United States influenced socially conscious American artist of the Depression era, who, between 1935 and 1943 hundreds of murals for public buildings under government-sponsored art programs. Great freedom and variety characterized the work of such muralist as Stuart Davis and Ben Shahn and the regionalist Thomas Hart Benton.

The influence of the muralist of the 1930s has been carried over into new schools of mural painting, beginning with the ghetto and counterculture urban wall painters of the 1960s and '70s and the graffiti artist whose work began to receive serious attention in the 1970's. The tradition of amateur mural making in neighborhoods lives on, while contemporary professional muralist are commissioned by entities ranging from municipalities to corporations.