The war began after a pronunciamiento by a group of generals of the Spanish Republican Armed Forces, under the leadership of José Sanjurjo, against the elected, leftist government of the Second Spanish Republic, at the time under the leadership of President Manuel Azaña. The rebel coup was supported by a number of conservative groups, including the Spanish Confederation of the Autonomous Right, monarchists such as the religious conservative Carlists, and the Fascist Falange.
The coup was supported by military units in Morocco, Pamplona, Burgos, Valladolid, Cádiz, Córdoba, and Seville. However, rebelling units in important cities—such as Madrid, Barcelona, Valencia, Bilbao, and Málaga—were unable to capture their objectives, and those cities remained under the control of the government. Spain was thus left militarily and politically divided. The Nationalists, now led by General Francisco Franco, and the Republican government fought for control of the country. The Nationalist forces received munitions and soldiers from Nazi Germany and Fascist Italy, while the Soviet Union and Mexico intervened in support of the "Loyalist", or "Republican", side. Other countries, such as Britain and France, operated an official policy of non-intervention, although France did send in some munitions.
The Nationalists advanced from their strongholds in the south and west, capturing most of Spain's northern coastline in 1937. They also besieged Madrid and the area to its south and west for much of the war. Capturing large parts of Catalonia in 1938 and 1939, the war ended with the victory of the Nationalists and the exile of thousands of leftist Spaniards, many of whom fled to refugee camps in southern France. Those associated with the losing Republicans were persecuted by the victorious Nationalists. With the establishment of a dictatorship led by General Francisco Franco in the aftermath of the war, all right-wing parties were fused into the structure of the Franco regime. A smaller but significant number of killings took place in areas controlled by the Republicans, normally associated with a breakdown in law and order. The extent to which Republican authorities connived in Republican territory killings varied.
At the end of the 19th century, the owners of large estates, called latifundia, held most of the power in a land-based oligarchy. The landowners' power was unsuccessfully challenged by the industrial and merchant sectors. In 1868, popular uprisings led to the overthrow of Queen Isabella II of the House of Bourbon. In 1873, Isabella's replacement, King Amadeo I of the House of Savoy, abdicated due to increasing political pressure, and the short-lived First Spanish Republic was proclaimed. After the restoration of the Bourbons in December 1874, Carlists and Anarchists emerged in opposition to the monarchy. Alejandro Lerroux, Spanish politician and leader of the Radical Republican Party, helped bring republicanism to the fore in Catalonia, where poverty was particularly acute. Growing resentment of conscription and of the military culminated in the Tragic Week in Barcelona in 1909.
Spain was neutral in the First World War. Afterwards the working class, the industrial class, and the military united in hopes of removing the corrupt central government, but were unsuccessful. Fears of communism grew. A military coup brought Miguel Primo de Rivera to power in 1923, and he ran Spain as a military dictatorship. Support for his regime gradually faded, and he resigned in January 1930. He was replaced by General Dámaso Berenguer and