Spanish Civil War: Foreign Intervention and Key Battles
Support for the Republic
The Republic relied heavily on support and military aid from the USSR, and to a lesser extent, France and Mexico. The USSR’s assistance with military equipment, drivers, and technical and political advisors proved crucial. Foreign troops intervened on the Republic’s side, notably the International Brigades, composed of volunteers driven by solidarity against the perceived international threat of fascism. Their defense of Madrid was particularly significant. The Republic financed the war using the gold reserves of the Bank of Spain.
Military Aid to the Rebels
The Spanish Civil War became a testing ground for new military equipment and tactics. Hitler and Mussolini agreed to Franco’s requests for military aid. This support was essential for transporting troops from Spanish Morocco to mainland Spain and advancing on Madrid. Germany sent tank units, defense forces, and aviation units organized into the so-called Legion. Mussolini’s contribution was even larger, consisting of the Corpo di Truppe Volontarie. Support also came from the Portuguese Estado Novo dictatorship. The Nazi and Fascist military aid was substantial and decisive for Franco’s eventual victory. The Republic consistently faced obstacles in securing similar levels of support. The rebels also received financial backing from Spanish capitalists and major Anglo-American multinational companies like Texaco, which provided petroleum, and Ford and General Motors, which supplied transport equipment.
The Battle of Madrid (1936-1937)
The rebels’ primary objective was the swift capture of Madrid. General Mola’s early attempts were thwarted, with General Fanjul taking refuge and awaiting reinforcements in the mountainous headquarters. The advance stalled in the Sierra de Guadarrama. With this setback, the focus shifted to the Army of Africa, commanded by Franco. Aided by German and Italian aircraft, the army began its transfer from Morocco to Spain.
A column of legionnaires and regular troops, led by Yagüe, initiated a rapid march toward Madrid, capturing Badajoz in Extremadura. Franco then chose to delay the Madrid offensive to relieve the Alcázar of Toledo, where rebel soldiers under Colonel Moscardó were besieged by Republican forces. Its liberation was a propaganda victory for Franco, who was subsequently appointed Generalissimo of the rebel forces by the Junta de Defensa de Burgos. This delay allowed the Republicans to organize their defenses. The Republican government relocated to Valencia, leaving a Defense Junta in Madrid, led by Generals José Miaja and Vicente Rojo. Trade unions and workers’ parties fostered resistance among Madrid’s citizens with the slogan “¡No pasarán!” (“They shall not pass!”), which became a rallying cry for Republican Spain.
The arrival of Soviet tanks, the first International Brigades, and the anarchist Durruti Column bolstered the morale of Madrid’s defenders. Fierce battles ensued in Casa de Campo, University City, and at the Puente de los Franceses (French Bridge), while the city endured relentless bombing by German aircraft. Despite this, Republican troops held their ground. Franco then shifted his strategy, aiming to encircle the city by cutting off the road to Valencia. The battles of Jarama and Guadalajara followed, where the newly formed Popular Army of the Republic defeated the Italian corps, forcing Franco to abandon the direct assault on Madrid. Meanwhile, Queipo de Llano’s troops occupied the province of Málaga.
The Fall of the North (1937)
Following the setbacks in Madrid, Franco adopted a war of attrition, focusing on systematic territorial gains and the destruction of the Republican army. Italy and Germany formally recognized Franco’s government. Franco then turned his attention to the industrial and mining regions of the north, which remained under Republican control.
The rebel offensive against Biscay, commanded by General Mola and supported by the Legion, commenced with devastating air raids. Incendiary bombs were dropped on the civilian populations of Durango and Guernica, the latter being razed to the ground. Mola died in a plane crash shortly thereafter. The dire situation in the north prompted the Republican government to launch an offensive in Brunete, north of Madrid, to alleviate the pressure. This offensive failed and did not prevent the fall of Santander. In a further attempt to save Asturias, an offensive was launched in Belchite (Aragon), but this too proved disastrous and could not prevent Franco’s troops from taking Gijón. The entire north then fell under “Nationalist” control.