The International Brigades were soldiers set up by the Communist International to assist the Popular Front government of the Second Spanish Republic during the Spanish Civil War. The organization existed for two years, from 1936 until 1938. It is estimated that during the entire war, between 40,000 and 59,000 members served in the International Brigades, including some 10,000 who died in combat. Beyond the Spanish Civil War, "International Brigades" is also sometimes used interchangeably with the term foreign legion in reference to military units comprising foreigners who volunteer to fight in the military of another state, often in times of war.
The Corps of Volunteer Troops was a Fascist Italian expeditionary force of military volunteers, which was sent to Spain to support the Nationalist forces under General Francisco Franco against the Spanish Republic during the Spanish Civil War, 1936–39.
Camillo Berneri was an Italian professor of philosophy, anarchist militant, propagandist and theorist. He was assassinated during the Spanish Civil War, presumably on the orders from Stalin's USSR.
The War in the North was the campaign of the Spanish Civil War in which the Nationalist forces defeated and occupied the parts of northern Spain that had remained loyal to the Republican government.
The Aragon Offensive was an important military campaign during the Spanish Civil War, which began after the Battle of Teruel. The offensive, which ran from March 7, 1938, to April 19, 1938, smashed the Republican forces, overran Aragon, and conquered parts of Catalonia and the Levante.
The Legionary Air Force was an expeditionary corps from the Italian Royal Air Force that was set up in 1936. It was sent to provide logistical and tactical support to the Nationalist faction after the Spanish coup of July 1936, which marked the onset of the Spanish Civil War.
The Arditi del Popolo was an Italian militant anti-fascist group founded at the end of June 1921 to resist the rise of Benito Mussolini's National Fascist Party and the violence of the Blackshirts (squadristi) paramilitaries. It grouped revolutionary trade-unionists, socialists, communists, anarchists, republicans, anti-capitalists, as well as some former military officers, and was co-founded by Giuseppe Mingrino, Argo Secondari and Gino Lucetti – who tried to assassinate Mussolini on 11 September 1926 – the deputy Guido Picelli and others. The Arditi del Popolo were an offshoot of the Arditi elite troops, who had previously occupied Fiume in 1919 behind the poet Gabriele d'Annunzio, who proclaimed the Italian Regency of Carnaro. Those who split to form the Arditi del Popolo were close to the anarchist Argo Secondari and were supported by Mario Carli. The formazioni di difesa proletaria later merged with them. The Arditi del Popolo gathered approximately 20,000 members in summer 1921.
The campaign of Gipuzkoa was part of the Spanish Civil War, where the Nationalist Army conquered the northern province of Gipuzkoa, held by the Republic.
The Battle of Irún was the critical battle of the Campaign of Gipuzkoa prior to the War in the North, during the Spanish Civil War. The Nationalist Army, under Alfonso Beorlegui, captured the city of Irún cutting off the northern provinces of Gipuzkoa, Biscay, Santander, and Asturias from their source of arms and support in France.
The Garibaldi Battalion was a largely-Italian volunteer unit of the International Brigades that fought on the Republican side of the Spanish Civil War from October 1936 to 1938. It was named after Giuseppe Garibaldi, an Italian military and political figure of the nineteenth century.
The Spanish Civil War was a military conflict fought from 1936 to 1939 between the Republicans and the Nationalists. Republicans were loyal to the left-leaning Popular Front government of the Second Spanish Republic, and consisted of various socialist, communist, separatist, anarchist, and republican parties, some of which had opposed the government in the pre-war period. The opposing Nationalists were an alliance of Falangists, monarchists, conservatives, and traditionalists led by a military junta among whom General Francisco Franco quickly achieved a preponderant role. Due to the international political climate at the time, the war had many facets and was variously viewed as class struggle, a religious struggle, a struggle between dictatorship and republican democracy, between revolution and counterrevolution, and between fascism and communism. According to Claude Bowers, U.S. ambassador to Spain during the war, it was the "dress rehearsal" for World War II. The Nationalists won the war, which ended in early 1939, and ruled Spain until Franco's death in November 1975.
The July 1936 military uprising in Melilla occurred at the start of the Spanish Civil War. The rebels seized the main garrisons of the Spanish Army in Africa and by 18 July had crushed the resistance of the army officers loyal to the Republican government. The supporters of the Second Spanish Republic were detained or shot.
The July 1936 military uprising in Barcelona was a military uprising in Barcelona, the capital and largest city of Catalonia, Spain on 19 July 1936 which contributed to the start of the Spanish Civil War. Most of the Spanish Army officers in the city supported the coup, but the Civil Guard, the Assault Guard and the Mossos d'Esquadra remained loyal to the Republican government. Furthermore, Barcelona was one of the strongholds of the anarchist union, the Confederación Nacional del Trabajo (CNT). The rebel troops were defeated after one day of bloody combat.
The Battle of Guadarrama was the first battle in the Spanish Civil War involving troops loyal to the Second Spanish Republic in the Sierra de Guadarrama. The battle took place in the last week of July and in early August 1936. The Nationalist side sent by General Mola was attempting to cross the mountain passes of the Sierra de Guadarrama and reach Madrid by the North, but the Republican side, made up of militiamen and troops disbanded by the government left Madrid to stop the Nationalists. The Republican side was successful and the Nationalist troops did not manage to cross the mountain passes.
The Huesca Offensive was an operation carried out during the Spanish Civil War by the Republican Army in June 1937 in order to take the Aragonese city of Huesca, which since the start of the war in July 1936 had been under the control of the Nationalist forces.
The Battle of Menorca took place in the island Menorca between 7 and 9 February 1939 during the Spanish Civil War.
Milicianas fought in the Spanish Civil War. They came from a culture with iconic fighters, and where women had been recently empowered through direct political engagement in political organizations and labor unions. The Dictatorship of Primo de Rivera saw women take more to the streets to protest and riot, though their actions were dismissed by male political leaders. The creation of the Second Spanish Republic led to an environment encouraging active political participation in broader Spanish society, and ultimately served to assist many women in their decision to head to the front, as the Government expanded rights for women, including the right to vote, divorce, go to school and stand for election.
The confederal militias were a movement of people's militia organized during the Spanish Civil War by the dominant organizations of anarchism in Spain: the National Confederation of Labor (CNT) and the Iberian Anarchist Federation (FAI).
The Ascaso Column was the third column organized in Barcelona at the beginning of the Spanish Civil War. It fought on the Aragon front, in Huesca, where it was joined by a battalion of Italian anti-fascists. During the militarisation of the confederal militias, it was reorganised into the 28th Division.
Antonio Cieri was an Italian anarchist and anti-fascist militant. A founding member of the Arditi del Popolo, he fought and died during the Spanish Civil War.
Spanish Republic 
Nationalists