The Spanish Civil War was fought from 17 July 1936 to 1 April 1939 between the Republicans, who were loyal to the established Spanish Republic, and the Nationalists, a rebel group led by General Francisco Franco. The Nationalists prevailed, and Franco ruled Spain for the next 36 years, from 1939 until his death in 1975.
The war began after a pronunciamiento (declaration of opposition) by a group of generals of the Spanish Republican Armed Forces under the leadership of José Sanjurjo against the elected 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, Cordova, 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 in 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 it out for the 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 left-leaning 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 fascist 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.
The war became notable for the passion and political division it inspired and atrocities were committed by both sides in the war. Organized purges occurred in territory captured by Franco's forces to consolidate the future 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.