The April 1937 air attack by German and Italian bombers on the Basque city of Guernica during the Spanish Civil War (1936–1939) horrified the world and was one of the defining moments in the development of modern airpower. Guernica, the Basque province of Vizcaya in northern Spain, was considered by Basques as their cultural, spiritual, and historical capital.
Following their failure to take Madrid in early 1937, Nationalist generals Francisco Franco y Bahamonde and Emilio Mola launched a major offensive in northern Spain that severed the Basque country from Republican Madrid and Catalonia. The Nationalist goal was to secure coal reserves, iron production facilities, and ports used by the Republican government. The chief objective was the city of Bilbao, the center of what became known as the Iron Ring.
Franco therefore ordered an all-out drive on the Basque country in which the Nationalists would make full use of German and Italian aircraft and artillery, primarily the planes of the German Condor Legion. Certainly not volunteers as Berlin claimed, the Condor Legion numbered about 5,000 regular Luftwaffe personnel and more than 100 aircraft. Generalleutnant Hugo Sperrle commanded the legion, with Colonel Baron Wolfram von Richthofen as chief of staff.
On March 31, 1937, General Mola announced his intention “to raze all Vizcaya to the ground.” Accordingly, on March 31, 1937, Condor Legion aircraft attacked the town of Durango, a rail and road junction east of Bilbao. The raid inflicted great damage and killed at least 137 people. Still, Nationalist forces on the ground found the going difficult. Sperrle and Richthofen were convinced that their Spanish allies were too cautious, and Richthofen worked out an agreement with Mola’s chief of staff, Colonel Juan Vigón, to permit German and Italian aircraft to act independently of Nationalist control and attack Republican troop concentrations “without regard for the civilian population.”
During the first three weeks of April, German and Italian aircraft supported Nationalist troops on the ground and regularly attacked Bilbao. By late April the Basques were feeling the pressure and began withdrawing toward Bilbao. Richthofen hoped to trap sizable Basque forces and toward that end ordered the destruction of the key Renteria Bridge, near Guernica. The Germans and Italians were coordinating their air operations in support of the Nationalists, and both committed bombers to this mission, although the bulk of the aircraft involved were German.
The raid began at 4:40 p.m. on April 26, a market day in Guernica, when a twinengine German Heinkel He-111 medium bomber appeared over Guernica. There was no fire from the ground, as the town had no antiaircraft guns, and the aircraft’s bombs fell not on the bridge but instead in Guernica itself. Twenty-five minutes later, three other He-111s appeared. Their bombs, released from several thousand feet, hit a candy factory near the bridge, turning it into an inferno that soon spread to the town. Bombs also struck the marketplace. Soon much of Guernica was on fire and obscured by smoke.
Five pairs of Heinkel He-51 fighters then arrived, passing back and forth and strafing civilians in the open. At 6:00 p.m. some 40 German trimotor Junkers Ju-52 bombers from Attack Bomber Squadron K/88 as well as several Italian SavoiaMarchetti 79s arrived, carrying a mix of high-explosive and incendiary bombs that were dropped from perhaps 12,000 feet. Because smoke and dust obscured the entire area, the pilots did not attempt to locate specific targets.
By the time the bombers departed, two-thirds of the buildings of Guernica had been leveled or were on fire. Fighter aircraft then again strafed the civilians trying to flee. Casualty figures from the attack remain in dispute. They range from 250 dead to as many as 1,654 dead and 889 wounded. The Renteria Bridge was unharmed.
The Germans were proud of what they had accomplished. Four days later Ricthofen wrote in his diary: “Guernica, city of 5,000 inhabitants, literally leveled.” He noted the success of the bomb mix and concluded, “Bomb craters are plainly to be seen—absolutely fabulous!” Clearly the Germans and Italians saw undefended Guernica as a legitimate target. Richthofen probably ordered the attack without consulting the Spaniards, including Franco.
Although the Germans saw the Spanish Civil War as a testing ground for military equipment and tactics, their raid on Guernica was not an experiment in the terror bombing of civilians. Much of the world perceived it as such, however, drawing false lessons from it as to the effectiveness of airpower in attacks on civilian centers. Guernica was a major story in the world’s press, giving the Spanish Republican government a powerful propaganda weapon against the Nationalists. The attack even became the subject of one of the world’s most famous paintings, Pablo Picasso’s Guernica. In a gesture of protest, Picasso would not allow the painting to be displayed in Spain until the fall of the Nationalist government.
The Nationalist side and the German government claimed that there had been no attack and that the fires and destruction in Guernica had been arranged by the Republicans to discredit the Nationalists. This lie was repeated in print as late as 1979, four years after Franco’s death. Anticipating an international investigation, as soon as Guernica was in Nationalist hands Sperrle sent men from the Condor Legion to clear out telltale dud bombs and bomb fragments.
Large, David Clay. “Guernica: Death in the Afternoon.” MHQ: Journal of Military History 1(4) (Summer 1989): 8–17.
Maier, Klaus. Guernica 26.4.1937: Die deutsche Intervention in Spanien und der “Fall Guernica.” Freiburg, Germany: Rombach, 1975.
Proctor, Raymond L. Hitler’s Luftwaffe in the Spanish Civil War. Westport, CT: Greenwood, 1983.
Ries, Karl, and Hans Ring. The Legion Condor: A History of the Luftwaffe in the Spanish Civil War, 1936–1939. London: Schiffer, 1992.