Today in Labor History April 26, 1937: The Nazis bombed Guernica, a town in the Basque region of Spain. Later that year, Picasso painted his famous painting, Guernica, in protest of the atrocity. This was during the Spanish Civil War. The Republicans, a coalition of anarchist, socialist and communist partisans, were fighting the Nationalists, led by the fascist, Francisco Franco. The Nazis bombed Guernica for two hours. They killed between 1,000 and 3,000 civilians, or 20-60% of the population.