Causes of the Spanish Civil War (1936-1939) include inequality and widespread poverty in Spain in the early 1900s. Spanish society was highly fragmented, and many different ideologies including anarchism, anarcho-syndicalism, and communism attracted large numbers of adherents. The communists resented the power of the Catholic Church, while the wealthy feared the spread of communism.

In 1931, the Spanish king went into exile, and a new democratic government took power. It made reforms that separated the church and state, reduced the power of the Church, and made attempts to weaken the power of the army. But, economic problems related to the Great Depression added to the turmoil in Spain.

In the 1933 elections, conservatives took over. In the April 1936 election, Leftists (the Popular Front) again were victorious, but right-wing factions did not accept the results of the election; there was fighting in the streets, and in July the army launched a rebellion. The army was also supported by the middle class, the Church, businessmen, and landowners; this side became known as the Nationalists. The other side, representing the leftist government, included middle class intellectuals and urban and rural workers; this side was known as the Republicans.

General Francisco Franco arrived with troops from Morocco and became the Nationalist leader. As the war unfolded, many European nations signed non-intervention agreements. However, Germany and Italy sent aid to the Nationalists, supporting Franco as a fellow fascist leader. About 30,000 foreigners served in International Brigades, supporting the Republicans.

The USSR also provided aid to the Republicans including sending advisors and small arms, as well as providing assistance building tanks, fighters, and bombers. However, the Spanish had to pay for this support. The Nationalists forces benefitted from German small arms, tanks and aircraft, and the support of the Luftwaffe. Moreover, Italy sent 70,000 troops as well as tanks and aircraft to support Franco in the war.

During the war, there were atrocities on both sides, including many attacks against civilians. An example is the German attack on the city of Guernica, where German bombing killed as many as 1,700 civilians. The war became a war of attrition. Major battles included battle at Badajoz, the first major battle, the battles for Madrid, and the battles of the Ebro, which were the bloodiest of the war.

The Republicans were finally forced to surrender in April 1939. The war cost Spain half a million deaths and a wave of refugees fled from Franco’s triumphant fascist dictatorship. Additional deaths were caused by starvation and the spread of disease.

The effects of the war were widespread destruction in Spain. Italy and Spain had used the war as an opportunity to train their troops and test their weapons. Art and literature were affected, including “For Whom the Bell Tolls” by Hemingway and the famous depiction of Guernica by Pablo Picasso.