On April 26, 1937, the Luftwaffe's Condor Legion and Italian aircraft firebombed Guernica, a Basque market town with no significant military value, in a coordinated attack lasting over three hours. The raid, one of the first aerial bombings of a civilian population, killed an estimated 200 to 1,600 people and inspired Picasso's famous painting.
It was market day, and Guernica's streets and squares were crowded with farmers and refugees when the bombers arrived shortly after 4 p.m. Waves of German Junkers and Italian Savoia-Marchetti aircraft dropped high-explosive and incendiary bombs for over three hours, deliberately targeting the town center while strafing people who fled into fields.
The attack was carried out at the request of Francisco Franco's Nationalist forces, eager to break Basque resistance during the Spanish Civil War, but the mission was planned and executed by German and Italian personnel testing new theories of terror bombing against civilian morale. Estimates of the dead vary wildly depending on the source, from Basque claims of over 1,600 to later, lower academic estimates, but eyewitnesses described a town reduced to rubble and fire.
News of the bombing reached the world quickly through journalists like George Steer, whose dispatches shocked international opinion. Pablo Picasso, already commissioned to create a mural for the Spanish Pavilion at the 1937 Paris International Exposition, transformed his outrage into 'Guernica,' a monumental black-and-white canvas of writhing bodies that became the 20th century's most enduring anti-war symbol.