The Spanish Civil War (1936–39) was the bloodiest conflict western Europe had experienced since the end of World War I in 1918.
It was the breeding ground for mass atrocities. About 200,000 people died as the result of systematic killings, mob violence, torture, or other brutalities.
The fighting displaced millions of Spaniards. Some 500,000 refugees fled in 1939 to France, where many of them would be interned in camps. 15,000 Spanish Republicans ended up in Nazi concentration camps after 1940.
The Spanish Civil War began on July 17, 1936, when generals Emilio Mola and Francisco Franco launched an uprising aimed at overthrowing the country's democratically elected republic. The Nationalist rebels' initial efforts to instigate military revolts throughout Spain only partially succeeded. In rural areas with a strong right-wing political presence, Franco's confederates generally won out. They quickly seized political power and instituted martial law. In other areas, particularly cities with strong leftist political traditions, the revolts met with stiff opposition and were often quelled. Some Spanish officers remained loyal to the Republic and refused to join the uprising.
Within days of the uprising, both the Republic and the Nationalists called for foreign military aid. Initially, France pledged to support the Spanish Republic, but soon reneged on its offer to pursue an official policy of non-intervention in the civil war. Great Britain immediately rejected the Republic's call for support.
Faced with potential defeat, Franco called upon Nazi Germany and Fascist Italy for aid. Thanks to their military assistance, he was able to airlift troops from Spanish Morocco across to the mainland to continue his assault on Madrid. Throughout the three years of the conflict, Hitler and Mussolini provided the Spanish Nationalist Army with crucial military support.
Some 5,000 German air force personnel served in the Condor Legion, which provided air support for coordinated ground attacks against Republican positions and carried out aerial bombings on Republican cities. The most notorious of these attacks came on April 26, 1937, when German and Italian aircraft leveled the Basque town of Gernike (Guernica in Spanish) in a three-hour campaign that killed 200 civilians or more. Fascist Italy supplied some 75,000 troops in addition to its pilots and planes. Spain became a military laboratory to test the latest weaponry under battlefield conditions.
The Spanish conflict quickly generated worldwide fears that it could explode into a full-fledged European war. In August 1936, more than two dozen nations, including France, Great Britain, Italy, Nazi Germany, and the Soviet Union, signed a Non-Intervention Agreement on Spain. The latter three signatories openly violated the policy. Italy and Germany continued to supply Franco's forces, while the Soviet Union provided military advisors, tanks, aircraft, and other war materiel to the Republic. Some scholars argue that the Non-Intervention Agreement benefited Franco, who could acquire armaments on credit from his allies, while the Republic had to pay hard currency to arms dealers to obtain often outdated weapons and find ways to transport these goods into the embargoed country.
In the United States, President Franklin D. Roosevelt's administration chose not to intervene officially in the conflict, although the President sought to clandestinely provide some aid to the besieged Republic after 1937. The Spanish Civil War divided American public opinion between those who supported the Republic and those who condemned the Republican forces for carrying out attacks on the Catholic Church. Isolationism too proved to be an effective motivation for non-intervention. Fears of war and foreign entanglements helped to shape American politics in the 1930s.
For many liberals and leftists throughout the world, the Spanish Civil War represented a dress rehearsal for World War II, a pending conflict between the forces of democracy and fascism. By the mid-1930s, fascism and authoritarianism seemed to be on the rise in Europe. In 1936, when Franco launched his rebellion, right-wing regimes were in power in Germany, Italy, Hungary, Romania, Poland, Portugal, Finland, Austria, and Greece. And openly pro-Fascist and pro-Nazi political parties existed in many other countries, including France, Great Britain, and the United States.
Some 35,000 to 40,000 volunteers from more than 50 countries rushed to join the International Brigades to defend the Republic. A smaller number of foreign recruits joined Franco's forces.
The Spanish Civil War engendered massive political violence, carried out by both sides on the battlefield and on city streets. The Nationalists included ultra-reactionary monarchists (Carlists), fascists (Falangists) as well as traditional conservatives, who viewed the Republic's supporters as “godless Bolsheviks” (Communists) who needed to be eradicated in order to create a new Spain. Franco's army also included Moorish troops from Morocco. The rebels portrayed the fighting as a “crusade,” a “holy war,” against a “Judeo-Masonic-Bolshevist” conspiracy. Antisemitic propaganda, including the notorious fictional work, The Protocols of the Elders of Zion, circulated throughout the Nationalist-held territories. The Nationalists also tried to combat Basque and Catalan nationalism, which was perceived as a threat to national unity.
The Republican forces (Loyalists) too included a broad spectrum of political positions from moderate democrats, liberals, and socialists to more radical Leftists, such as Communists (both of the Stalinist and Trotskyist varieties) and Anarchists. On occasions, this coalition broke down into internecine violence.
The Spanish Civil War proved to be a breeding ground for mass atrocities, carried out by belligerents eager to eradicate their ideological opponents. About 500,000 people lost their lives in the conflict. Of these, about 200,000 died as the result of systematic killings, mob violence, torture, or other brutalities. Anarchists and other radicals often took out their anger against the Catholic clergy, whom they saw as an obstacle to major reform. Almost 7,000 Catholic priests, monks, and nuns were killed, primarily in the first months of the revolt. By May 1937, most of the mass killings of priests by Leftist radicals subsided. Francoist forces too killed liberal-minded or Loyalist clergy.
The Nationalists waged a brutal war against the Republic's supporters. Republican women were raped or were publicly humiliated by having their heads shaved. By 1940, more than 500,000 individuals were rounded up and sent to about 60 concentration camps. Large numbers of prisoners were conscripted for forced labor or to fight in Franco's army or tried by military courts.
During the war itself, 100,000 persons were executed by the Nationalists; after the war ended in spring 1939, another 50,000 were put to death. Martial law remained in place in Franco's Spain until 1948, and former Republicans were subjected to various forms of discrimination and punishment.
The fighting and persecution resulted in several million Spaniards being displaced. Many fled areas of violence for safe refuge elsewhere. Only a few countries, such as Mexico and the Dominican Republic, opened their doors to Spanish refugees. When the Spanish Civil War ended in 1939, with Franco's victory, some 500,000 Spanish Republicans escaped to France, where many were placed in internment camps in the south, such as Gurs, St. Cyprien, and Les Milles. Following the German defeat of France in spring 1940, Nazi authorities conscripted Spanish Republicans for forced labor and deported more than 30,000 to Germany, where about half of them ended up in concentration camps. Some 7,000 of these became prisoners in Mauthausen; more than half of them died in the camp.