Eighty years ago, received a commission that would forever change his career.

The Spanish Republic—then in the throes of the Spanish Civil War, against future dictator Francisco Franco—had asked Picasso, among several other prominent artists, to create a painting for its pavilion at the Paris International Exposition of 1937. The work he made was Guernica, the now-legendary, mural-sized painting inspired by the bombing of a small Basque town, which now resides at the Museo Nacional Centro de Arte Reina Sofía in Madrid.

While numerous works by Picasso have been crowned masterpieces—like Les Demoiselles d’Avignon (1907), which is said to have set Western in motion—Guernica stands alone in the artist’s prolific oeuvre. Why has this painting, in particular, struck a chord with generations of viewers?

In an exhibition currently open at the Reina Sofía to mark the 80th anniversary of the creation and display of Guernica, titled “Pity and Terror: Picasso’s Path to Guernica,” curators Timothy James Clark and Anne M. Wagner delve into the artist’s production during the decade prior to the work’s inception. These earlier preoccupations include the artist’s interior scenes and depictions of women from the mid-1920s and ’30s, two themes in Picasso’s work that would ultimately surface in Guernica.

In the mid-’20s, around the time that Picasso became involved with , he was painting interiors with still lifes, featuring objects like musical instruments and fruits. And initially, these works conveyed pleasure. But, as Wagner explains, the interior space soon became claustrophobic. “Its pleasure seemed to be charred and burnt up,” she says. “It became a theater for drama.”

This shift occurred amid the tumultuous World War I recovery efforts in the U.S. and Europe, the years preceding the devastating stock market crash of 1929. During this period, Picasso and the Surrealists were examining the dark spaces of the human psyche. “Picasso knew very well that being a human involved terror, tragedy, excess, and violence,” Wagner notes, “and he believed very much that the psyche is a place in which one plays out the unconscious mind.”

The Three Dancers (1925), a large painting now in the Tate’s collection, is a prime example of Picasso’s work of this era. (Wagner notes that, later in life, Picasso considered it to be his greatest work.) “It’s a wild picture, full of a kind of excess,” Wagner says. “For Picasso, what’s now inside the room is not so much still life objects, but it’s the bodies of women, now treated in an immensely complex and defamiliarizing way.”

Notorious for his relationships with women, Picasso portrayed his lovers with affection in private works, but these depictions diverged markedly from his public paintings of women.

“For his public art, he was considering how women’s bodies could be monumental or architectural,” says Wagner, “how they could be traps or machines; how they could be the index of a different kind of reality, and how they could also be monstrous.” In the years leading up to Guernica, paintings and sketches evidence the artist’s ruminations on the symbolism that could be conveyed through manipulation of the female body—experimentations that find their resolution in Guernica.

Despite reports of the great speed with which Picasso created Guernica, it didn’t come out of nowhere. It is the result of years of artistic production, as well as the artist’s personal investment in the fraught politics of Spain, where his family was still living.

While the German and Soviet pavilions at the Paris International Exposition of 1937 were giant architectural displays of authority and power, the Spanish Republic, less than a year into the Civil War and in need of financial support, opted for a modest, efficient structure, and filled it with world-class art.

Known for its reverence toward artists and intellectuals, the Republic tapped creatives at the forefront of the ’30s avant garde, like and . Picasso received the commission for a mural-sized painting in January 1937.

While artworks created for the Republican pavilion were intended to serve as political vehicles (commissioned by an anti-fascist regime), Picasso’s original plan for his work was, at least at face value, decidedly apolitical. According to Wagner, the artist was at a loss as to what he should paint. Initial sketches for the work depict a painter in his studio, facing a nude model who reclines on a sofa.

It was tragedy that led him to change course.

On April 26, 1937, Franco ordered the Nazi Condor Legion (loaned to Franco by Germany) to drop bombs over the small town of Guernica. It was a market day; civilians, predominantly women and children, were convened outdoors in public squares. As the first place where democracy was established in Spain’s Basque region, the town was a symbolic target. The brutal bombing, which killed hundreds of people (the number is contested, and reports vary between 200 and 1,700) and injured as many as 900 others, was the first instance in the Spanish Civil War in which a defenseless city was attacked.

“One of the things you can immediately glean from the whole spectrum of imagery around the Spanish Civil War was that there was a very public awareness of what was happening to civilian bodies—women and children,” Wagner notes. Indeed, the Spanish Civil War was the first war of its kind to have a press photography corps on the front lines, and like countless others, Picasso opened his morning paper in Paris on April 27th to find devastating images of the destruction of Guernica.

Though Picasso was already a known leftist—he had created a pair of etchings, titled the Dream and Lie of Franco (1937), which were reproduced and sold in order to raise funds for the Republic—the bombing struck him with particular force. And on May 1st, he took to his studio on Rue des grands Augustins, and began new sketches for the commission.

By mid-June, the work was finished; the Surrealist artist captured the various iterations the composition went through in a series of photographs. In July, Picasso delivered the finished work to the Republican pavilion, where it quickly became the centerpiece, flanked by Calder’s Mercury Fountain (1937) and Miro’s The Reaper (1937).

Guernica portrays a frenzied tangle of six human figures (four women, a man, and a child), a horse, and a bull; the action transpires within a claustrophobic, low-ceilinged interior, below an overhead lamp that appears to burst with light. While, as Wagner points out, hints of Picasso’s original composition (the interior of an artist’s studio) remain, the scene can clearly be read as the emotional and physical aftermath of war and violence.

While Picasso never made explicit to the public the symbolism behind each of Guernica’s figures and objects (“It’s up to the public to see what it wants to see,” he once said), much of it can be taken at face value. At the same time, art historians have, for decades, split hairs over the intentions behind nearly every brushstroke.

Most direct, perhaps, are the contorted expressions of the women, suffering physical agony and mental anguish. “You can see that the kinds of deformation are Picasso’s devices to register pain and suffering,” Wagner explains. The artist conveys their desperation through sharp, pointed tongues; and sorrow through tear-shaped eyes.

On the far left, one woman wails towards the sky while cradling a limp, lifeless child in her arms; another roars, her arms shooting upward as she’s consumed in flames; another emerges from an open window, wielding a torch. This third woman is at times interpreted as a sign of hope. Each woman is portrayed through amorphous shapes and jutting angles, their bodies at once cobbled together and falling apart.

On the floor, a figure who has been identified as a soldier, lies in pieces—perhaps a personification of the fledgling Republic. His dismembered arms are criss-crossed with gashes. One hand forms a tight fist—a symbol of the Republic—around a broken sword.

The overhead lamp has been read as symbolic of a bomb, though others have taken its form (shaped like an eye, with the light bulb as its iris) as a nod to the eye of god.

The bull and horse have drawn varying interpretations. Most trace back to the animals’ roles in the traditional Spanish bullfight, where horses can become collateral damage, and the bull is wounded to the point of death. In contrast, though, some have theorized that the bull, which lacks the emotional and physical expression of the rest of the figures, is an emblem of Franco or fascism. Still others believe the bull is representative of Spanish heritage—a stoic and unwavering witness to the tragedy.

Picasso’s visual language, however, transcends the particulars of a single Spanish tragedy to become universal. “It’s grand and intense and specific—you know what’s happening is about pain and death. But it’s not the case that you would say ‘Aha, that’s Spain,’” Wagner notes. “It has great applicability because it seems to be appropriate to so many different contexts.”

The current show at the Reina Sofía is titled after the disparate emotions that the painting conjures: pity and terror. “It makes you feel some of the tragedy of human existence,” says Wagner. “If you can feel simultaneously terror and pity for that plight, you’ve had that full throated, full-minded engagement with that experience.”

Following the close of the Paris Expo, Guernica went on tour in Europe. After the war ended, as Franco took power and the Republic folded, the painting continued to travel, and helped to raise funds for Spanish Republican refugees who had fled the country. It featured in the 1939 Picasso survey exhibition at the Museum of Modern Art in New York, and Picasso would stipulate that MoMA act as Guernica’s guardian.

Between 1939 and ’52, Guernica traveled to art institutions across the U.S.; thereafter, it was exhibited in Brazil and throughout western Europe—until 1958, when it was returned to MoMA and deemed no longer fit to travel. Decades of transport, including stretching and restretching the canvas on many occasions, had left the painting in a precarious physical state. It remained in New York until 1981.

It was during this time span that Guernica took on a life beyond the canvas. It became a stand-in for Dresden, Berlin, Hiroshima, synonymous with places where defenseless civilians came under attack. And in step, it began to take on particular resonance for anti-war protestors.

“We take it for granted that Guernica is symbol of modern warfare,” Wagner says, adding that in curating the 80th anniversary exhibition, they came across images showing reproductions of Picasso’s masterpiece being carried in protests all over the world, from Calcutta to Ramallah to South Carolina.

In turn, as with many great works of art, contemporary artists began to respond to Guernica in their own work, appropriating its imagery to respond to themes of war and violence.

While Picasso was still alive, he understood the political potency of Guernica. As early as 1939, when World War II broke out, he was surveilled by Nazis, due at least in part to Guernica’s resounding message. It’s said that a Nazi soldier once visited Picasso’s Paris studio, pointed to a reproduction of Guernica on the wall, and asked the artist, “Did you do that?” Picasso responded: “No, you did.”

“He had to stand up for this painting,” Wagner explains. “It became something whose fate he had to be very concerned about. He knew that he had done something unique and grand and important, and he knew just like he knew his name was Pablo that it could not go back to Spain.” To ensure the painting’s safety, he had a legal document drawn up that stipulated it should not enter Spain until democracy had been established there.

In 1981, six years after Franco died, and eight years after Picasso died, Guernica finally returned to Spain. Still a polarizing force for the nation, which was recovering from nearly four decades of dictatorship, it was shown under bulletproof glass.

The glass was removed in 1995, but Guernica’s raw political might has not wavered. In 2003, for example, controversy stirred when a tapestry reproduction of Guernica at the United Nations in New York was covered up by a blue curtain. It would have been the backdrop for Colin Powell as he gave a speech proposing U.S. involvement in the war in Iraq. (There are conflicting reports as to the reason for the cover-up, with some U.N. officials claiming reporters found the painting visually distracting on camera.)

Wagner notes that Picasso made significant political works following Guernica, though none would achieve the same exposure and resonance. Guernica became a marker of humanity, the message of which is still understood by people all over the world. Wagner may put it best: “It was a tremendous circumstance for Picasso and the history of art, Republican art, protest art, and humankind.”