At the age of 56, Picasso was riding a wave of personal and artistic success that would have been the envy of any artists. The Spanish Republican Government honored him above all others with an invitation to paint a mural for the Spanish Pavilion of the Paris World's Fair. He was having important shows in New York, Paris, London, and Germany. His work was bringing huge prices. The Museum of Modern art sold a Renoir to raise money a part of the money needed to purchase his Les Demoiselles d'Avignon for $24,000. (A huge price at the time for a living artist). Then on April 26, 1937, he was staggered by an event in his homeland that unleashed a creative outrage that was monumental even by Picasso's standards. Planes borrowed from Hitler by Generalisimo Ferdenand Franco, completely laid waste the small Basque town of Guernica in the first known use of saturation bombing in the history of warfare.
Picasso had his subject for the Spanish Pavillion mural! He began sketches for it less than a week later, ressurrecting motis from numerous earlier works as well as new elements. He started painting on May 11th. With his mistress at the time, Dora Maar, photographing each step of the process, he completed the 26' by 11' 6" tall canvas in an incredible three weeks of feverish effort. Even for Picasso the work was stark. Limiting himself to powerful black, pristine white, and modulating grays, Guernica screamed for all the world to see and, figuratively speaking, HEAR, the monstrosity of Franco's Spanish Civil War. Even after it was finished the impact upon Picasso's creative output was indelible. Motifs from the painting continued to show up in his work for months afterward, and the impact the painting had upon the rest of the world stamped even MORE indelibly the horrors of modern warfare.