Hardly any event shaped Spanish history as much as the three-year civil war. Even today, the after-effects of the conflict, which separated society into two camps – nationalists and republicans and, later, victors and vanquished – remain perceptible.

“Spaniards! […] The nation calls upon you for its defense!” With these words General Francisco Franco Bahamonde called for a coup against the Spanish Republic on July 18, 1936. The highly decorated and influential military officer, who had earned a reputation in the Spanish-Moroccan War (1921–1926), was a latecomer to the coup d’état. Ten years earlier, Spain had already been under the rule of a military dictator, General Primo de Rivera. After the fall of Primo in 1931, the Spanish King Alfonso XIII. fled the country, as he had politically supported the dictator. The Second Republic, declared on April 14, 1931, was soon dominated by socialist and reformist forces, who aimed at overcoming Spain’s backwardness as regards central European modernity. The four central reform projects of the Republican governments – land reform, separation of church and state, reduction of the officer corps, autonomy for Catalonia and the Basque Country – met with the disdain of the traditional elites.

In this climate of societal polarization, the army once again reached for power. Planned as quick coup de grâce, the military takeover turned into a long and strenuous civil war, in which Spain slowly bled to death. While the central cities and industrial centers like Madrid, Barcelona and Bilbao, in addition to major parts of the south and the east, initially remained under the control of the Republic, the putschists won in Galicia and North Castille, as well as on the Balearic and Canary Islands. While the frequently irregular combat units of socialists, communists, anarchists, and progressive moderates fought for the Republic, conservatives, nationalists, devout Catholics, monarchists, and the fascist Falange Party supported the military coup. In this sense, the conflict between civil and military leadership developed into a “fratricidal war,” in which the ideal of a progressive, egalitarian, secular and autonomist Spain collided with the conception of the “eternal Spain” of Catholic faith, territorial unity, and the hegemony of monarchy, church, and the military.

The Spanish Civil War became the battlefield of European ideologies in an age of extremes. From early on, the putschists enjoyed the support of Fascist Italy and Nazi Germany. German JU 52 planes thus carried the putschist Army of Africa from Morocco across the Strait of Gibraltar. The flying squadron of the German Legion Condor and the Italian Aviazione Legionaria bombarded Guernica, the holy city of the Basque Country, destroying it almost completely. In the meantime, the Spanish Republic received arms shipments, ammunition, and T-26 tanks from the Soviet Union, paid for by the Banco de España. The Communist International mobilized approximately 50,000 combatants from all across Europe for the International Brigades. The liberal democracies of the West (France, Great Britain, and the United States) opted for a policy of nonintervention and thereby indirectly contributed to the victory of the nationalist military under General Franco. After three years, approximately 300,000 casualties, and 500,000 refugees, the war ended on April 1, 1939.