Artistic Testimony

Assigned to paint a mural for Spain's pavilion at the 1937 World's Fair in Paris, Picasso decided to represent the bombing of Guernica by German planes backing the right-wing forces of General Francisco Franco during Spain's 1936-39 Civil War.

The attack on April 26, 1937 leveled three-quarters of the historic town, killing hundreds of the roughly 6,000 people which called it home at the time.

"In the panel on which I am working, which I shall call Guernica, and in all my recent works of art, I clearly express my abhorrence of the military caste which has sunk Spain in an ocean of pain and death," Picasso was quoted as saying as he worked on the mural.

History of a painting

Today, marking the 70th anniversary of the attack by the Nazi's Condor Legion on the Basque town, an exhibition at the Wall Museum in Berlin entitled "Pablo Picasso. Guernica. History of a Painting" explores the genesis of a unique work that is considered by many as modern art's most powerful anti-war symbol.

"Picasso created a painting that is still very moving," said director of the Berlin Wall Museum Alexandra Hildebrandt. "It doesn't show airplanes or enemies. It's filled with dead and injured bodies. It could've carried the name of 'Dresden' or 'Hiroshima.'"

"Thanks to Picasso's famous painting, Guernica's name has not been forgotten, which is what happened to many other places with a similar destiny," Hildebrandt said.

The Berlin exhibition, which opened on Wednesday, has been set up by Spanish book publisher and curator Jacobo Armero.

A symbol of national pride

For many Basques "Guernica" is an important symbol of their national identity as the town is considered the centre of their cultural traditions.

The town was once home to an oak tree which Spanish kings would stand beneath and vow to respect an ancient code giving the independent-minded Basques special rights. The tree survived the bombing but died during a heat wave in 2003 and was replaced two years later.

After Franco won the civil war and established a dictatorship, Picasso arranged for the Museum of Modern Art (MoMA) in New York keep the painting for as long as he was in power.

During the Vietnam War, the room housing "Guernica" at the US museum became the site of occasional anti-war vigils.

Franco died in 1975 -- two years after Picasso -- and in 1981 the painting arrived in newly democratic Spain where it was housed first in an annex of Madrid's Prado museum before being moved to the Reina Sofia, which is named after Spain's current queen.

Around the world

The mural, which is 3.5 metres (11 feet) tall and 7.8 metres wide, was exhibited in more than 50 different palces around the world between 1937 and 1957, including Brazil, Germany and the United States.

The frequent moves during this time damaged the painting and it is now very fragile, the head of the museum's conservation department, Jorge Garcia, told AFP last year.

"It is unthinkable to wrap it up again, anyone who desires this is crazy," he said at the time.

The 70th anniversary of the bombing has also led to renewed calls for Picasso's painting to be put on display in the town. Museum directors and the central government in Madrid turned down the request, saying the painting was to fragile to be moved. Basque government officials said they would now try to have the painting moved to Guernica in time for the 75th anniversary of the attack.