The Spanish Civil War began on July 18, 1936, when right-wing military officers launched a revolt in Spanish Morocco. Within three days, the rebels — known as Nationalists — had seized Morocco, most of northern Spain, and several key cities in the south. In cities like Madrid, however, Republican forces held their ground and crushed the uprising before it could take full hold. What followed was nearly three years of brutal, total war that left up to a million people dead — the deadliest conflict in Spanish history.
To understand how the war started, you have to go back to 1931. That year, King Alfonso XIII authorized elections, and Spanish voters overwhelmingly chose to abolish the monarchy and create a liberal republic. Alfonso went into exile, and the Second Spanish Republic was born, led by middle-class liberals and moderate socialists. But the new government had powerful enemies: the landed aristocracy, the Catholic Church, and a well-organized military clique all opposed the Republic’s direction. When conservative forces won back control of the government in the 1933 elections, the political fault lines deepened sharply.
In the years leading up to the war, Spanish streets were already scenes of intense political conflict. Socialists launched a revolution in the mining districts of Asturias, and Catalan nationalists rose up in Barcelona. General Francisco Franco crushed the so-called October Revolution of 1934 on behalf of the conservative government, earning him a promotion to army chief of staff in 1935. When the leftist Popular Front coalition won the February 1936 elections, nervous military officers began to plan a coup. Franco was quietly reassigned to the Canary Islands, far from the Spanish mainland.
Franco reluctantly agreed to join the military conspiracy scheduled to begin in Morocco at 5 a.m. on July 18, 1936, and in mainland Spain 24 hours later. The staggered timing was deliberate — it gave the Army of Africa time to secure Morocco before crossing to Spain’s Andalusian coast. On the afternoon of July 17, however, the rebels’ plan was discovered in Melilla, Morocco, forcing them into premature action. The cities of Melilla, Ceuta, and Tetuan fell quickly to the Nationalists, aided by conservative Moroccan troops. From the Canary Islands, Franco broadcast a message calling on all army officers to join the uprising.
Across mainland Spain, garrisons rose in revolt on July 18. The Republican government — slow to act and reluctant to arm workers and peasants — lost control of many areas within days. Nationalist forces took hold of conservative regions like Navarre and Old Castile almost immediately. A naval revolt by Nationalist officers largely failed, as sailors’ committees took over warships and secured several coastal cities for the Republic. But Franco’s move to transport his Army of Africa from Morocco to mainland Spain was a turning point. These experienced soldiers quickly overran large Republican territories in central and northern Spain.
The Nationalists received direct military support from Nazi Germany and Fascist Italy. Germany sent its Condor Legion — a force of aircraft, tanks, and experienced crews — while Italy contributed troops, planes, and artillery. The Republicans, on the other side, received weapons and advisors from the Soviet Union. They also drew thousands of foreign volunteers who formed the International Brigades, made up of communists, socialists, and anti-fascists from France, the United States, Britain, and elsewhere. The most significant contribution of these brigades was helping defend Madrid, which came under siege in November 1936.
Dolores Ibárruri — known as La Pasionaria — became one of the most recognizable voices of the Republican cause. A Communist Party leader, she delivered fiery speeches that rallied workers, soldiers, and women to fight for the Republic. Her phrase “No pasarán” (They shall not pass) became a defining slogan of the defense of Madrid.
The fighting was ferocious from the start. In August 1936, Republican militiamen defending the city of Badajoz were killed in large numbers as Franco’s Army of Africa pressed northward toward Madrid. Both sides carried out executions of captured fighters and political opponents throughout the war.
Street fighting was a defining feature of the war in its opening months. Republicans and Nationalists battled block by block through villages and cities alike, often with little more than rifles and improvised barricades. The city of Toledo became one of the most intense early battlegrounds, as Republican forces tried to dislodge Nationalist troops who had fortified themselves inside the historic Alcázar fortress.
The war brought swift and brutal reprisals in the Republican-held capital. A prison in Madrid became the site of mass executions of Nationalist politicians and military officers in August 1936. When the city came under siege that November, hundreds more prisoners were pulled from their cells and shot in the nearby town of Paracuellos de Jarama.
Anti-clerical violence was another defining element of the Republican side’s conduct in the early weeks of the war. The Catholic Church had openly backed Franco and the Nationalists, and Republican supporters responded with widespread attacks on religious institutions. Churches were looted and burned, and in Barcelona, the bodies of nuns were exhumed from a monastery and put on public display. These acts were both expressions of deep anti-clerical rage and deliberate attempts to shock and humiliate the Church.
In the northern Basque region, Republican soldiers fought to hold territory against a Nationalist advance backed by German and Italian air power. The Campaign of Gipuzkoa saw the Nationalists eventually conquer the northern province, forcing Republican troops to dig in and retreat under constant pressure. Cities like Irun — on the French border — were bombed and burned as they fell.
Women played active military roles on the Republican side from the war’s earliest days. Female militia units like the Batallón de Acero (Battalion of Steel) fought alongside men at the front, carrying weapons and taking part in combat. In Barcelona, women armed with rifles stood guard in the streets during the summer of 1936.
Civilians suffered enormously throughout the conflict. Bombing raids on cities and towns killed thousands of non-combatants and left families homeless and destitute. Children were among the most visible victims — photographed beside rubble, fleeing their homes, or waiting in long lines for basic food rations.
General Francisco Franco arrived in Spain after the coup to take personal command of the Nationalist forces. Spain’s fascist party, the Falange, unified all Nationalist factions under his authority in 1937, making him the undisputed leader of the rebellion. His Army of Africa — hardened by years of colonial warfare in Morocco — formed the professional backbone of the Nationalist military machine.
On November 2, 1937, the German Condor Legion carried out an air attack on the city of Lleida (Lerida) that became one of the most notorious atrocities of the war. The bombing targeted a school called the Liceu Escolar de Lleida. Forty-eight children and several teachers were killed in that single strike. In total, 300 people died in the November 2 bombings. The city was bombed again during the 1938 campaign that brought it under Nationalist control.
The Battle of Teruel, fought between December 1937 and February 1938 during the worst Spanish winter in twenty years, was one of the bloodiest engagements of the entire war. The city changed hands multiple times — first falling to Republican forces, then recaptured by the Nationalists. Both artillery and aerial bombardment pounded the city relentlessly throughout the two-month fight. Combined casualties for both sides exceeded 140,000.
By 1937, the war had begun to displace entire civilian populations. The northern city of Santander saw children evacuated as Nationalist forces advanced. Families fled with whatever they could carry, many of them never returning to their homes.
The Battle of Brunete in July 1937, fought fifteen miles west of Madrid, was a Republican attempt to relieve the pressure the Nationalists were putting on the capital and on the northern front. The Republicans made early gains but were ultimately forced to retreat, suffering heavy casualties in the process.
The bombing of Guernica on April 26, 1937, stands as one of the most infamous events of the entire war. The German Condor Legion and the Italian Aviazione Legionaria carried out the attack under Operation Rügen, targeting the historic Basque cultural city. The Basque government reported 1,654 people killed. The attack demonstrated to the world the devastating potential of modern aerial bombing against civilian targets.
In the Extremadura region, Nationalist forces systematically executed Republican supporters following their military victories. Between 6,600 and 12,000 Republican supporters were killed by Nationalist forces in the region. The campaign culminated in the Battle of Badajoz in August 1936, after which Franco’s Army of Africa pivoted northward to begin its march toward Madrid.
By early 1939, the war was in its final phase. Barcelona fell to Nationalist forces in January 1939, and the rest of Catalonia collapsed shortly after. Nationalist troops paraded through the city’s streets as Republican resistance disintegrated. The Soviet Union had recognized the futility of continued support, and the International Brigades had already been withdrawn.
In Madrid, civilians found shelter deep underground in the city’s metro stations as Nationalist bombs fell above them. The siege of Madrid lasted from November 1936 until the very end of the war, making it one of the longest urban sieges of the conflict.
Before the war began, political tensions had already been building for years. In February 1936, crowds gathered outside Barcelona’s prison to welcome the release of left-wing political prisoners, including Catalan nationalists who had been jailed after the 1934 uprising. These scenes of celebration in the streets masked the intensifying crisis below the surface of Spanish political life.
The February 1936 elections were marked by violence. Assault Guards maintained security on election day, but six people were killed during the voting and around thirty more were injured. The election brought the Popular Front to power, deepening the fears of right-wing officers and landowners who had long feared a leftist takeover.
As the Nationalists consolidated control of Madrid in March 1939, Republican prisoners of war were marched through the city’s streets in plain view. The Republican cause was finished. Its leaders had tried to negotiate peace terms, but Franco refused to offer any. Madrid surrendered on March 28, 1939, ending the Spanish Civil War.
The Republicans depended heavily on Soviet supply ships for weapons and materials. At the naval base in Cartagena, crowds gathered at the docks to watch Soviet cargo ships unload their supplies — a moment that captured both the international nature of the conflict and how critical outside aid had become to keeping the Republic fighting.
In Tarragona, which surrendered on January 14, 1939, soldiers from the 5th Division of Navarre knelt in the streets for a public thanksgiving service after taking the city. The religious dimension of the Nationalist cause was ever-present — Franco framed his movement as a crusade to protect Catholic Spain from godless communism.
Germany’s Condor Legion fighters returned home in May 1939 after Franco’s victory was complete. At the port of Vigo, they were surrounded by Hitler Youth and Hitler Maidens from the local German community as they boarded trains home. The Condor Legion had given Germany’s military a live combat testing ground for new aircraft, tactics, and aerial bombing techniques.
Nationalist air raids killed children across Spain’s cities. In Barcelona in 1938, the bodies of several children killed in a bombing raid were laid out in the street. These images circulated internationally, fueling outrage in countries like Britain, France, and the United States — though their governments maintained policies of non-intervention.
When the Nationalists captured a city, the aftermath was swift and harsh. Republican supporters were arrested and led away. Refugees sat among the ruins of buildings, surrounded by their belongings, with nowhere to go. Propaganda banners appeared almost immediately on bombed-out walls, marking the new order taking hold.
Food shortages were a constant reality for civilians on the Republican side. In Barcelona, hungry women and children formed long lines outside milk depots every day, waiting for their rationed supply. These scenes of ordinary people enduring the grinding hardship of a prolonged siege became some of the most widely reproduced images from the war.
The Alcázar of Toledo became one of the war’s most storied early sieges. Nationalist troops held the fortress against Republican forces for months, and when Franco’s Army of Africa relieved the siege in September 1936, the Alcázar was left in near-total ruin — but it became a powerful symbol of Nationalist resistance.
In the Basque Country, Nationalist and Republican forces clashed at the mountain town of Irun, just across the border from France. The town fell to the Nationalists around September 4, 1936, and was left largely in ruins by the fighting and fires that accompanied its capture. A militiaman fleeing across the international bridge at Behobia was photographed mid-retreat — one of many images that captured the human cost of the Nationalist advance in the north.
Anti-clerical violence reached its most extreme expression in the destruction and desecration of Catholic institutions. Across Republican-held Spain, churches were gutted, their contents burned in the streets. In Barcelona, Republican supporters exhumed the corpses of nuns from a monastery and displayed them publicly on a wall. These acts were documented by photographers and used by the Nationalist side as powerful propaganda to portray the Republic as godless and savage.
In Seville on July 18, 1936, the military uprising that helped spark the war took shape in the streets. Nationalist General Gonzalo Queipo de Llano seized the city in a bold and largely improvised operation, using radio broadcasts and psychological pressure to prevent larger resistance from Republican supporters and workers.
One of the early Republican victories came in Madrid itself, at the Montaña Barracks. Anti-fascist militia forces stormed the garrison, which was held by Nationalist troops under General Joaquín Fanjul. The militia took the barracks in July 1936 and surveyed their casualties afterward — a moment captured in photographs that showed both the cost of the fight and the determination of those defending the Republic.
The Battle of Teruel produced some of the war’s most harrowing images. Corpses of Republican soldiers lay frozen on the Aragon front in December 1937, the bitter winter cold adding another layer of misery to the fighting. American writer Ernest Hemingway visited the front at Teruel on December 21, 1937, speaking with Republican soldiers before they went into action. Hemingway was one of several prominent foreign writers who covered the Republican side of the war.
At Gibraltar, British sentries guarded the only entry point through which Spanish refugees could cross to safety. As Falangist victories mounted in Spain, Britain reinforced the garrison and fortifications at Gibraltar, recognizing that the strategic harbor had taken on new importance in a rapidly shifting Mediterranean political landscape.
Manuel Azaña served as Spain’s reformist Prime Minister and was elected President of the Republic by parliament on May 10, 1936, taking over from conservative Niceto Alcalá-Zamora. His election came just months before the military uprising, and he would spend the war years trying desperately to hold together a fractious coalition of communists, socialists, anarchists, and liberal republicans against an increasingly powerful Nationalist military.
The Condor Legion’s Heinkel He 111 bombers were among the most advanced aircraft deployed in the Spanish Civil War. Ground crews prepared them for mission after mission against Republican targets, giving Germany’s air force real-world experience with precision bombing that would prove directly applicable in the coming world war.
Franco’s Army of Africa included Moroccan soldiers — known as Regulares — who were experienced, professional fighters. Their deployment on the mainland shocked many Spaniards, as they were seen as foreign troops being used against Spanish citizens. Their presence in the Nationalist ranks was a mark of how quickly and effectively Franco had moved to secure colonial military resources at the start of the war.
The Republican Navy’s rank-and-file sailors were largely loyal to the Republic. In most cases, crews stopped their officers from joining the Nationalist uprising — often executing them on the spot. Despite holding several warships, the Republican Navy was disorganized and never played a decisive role in the conflict. Members of the Navy who remained loyal to the Republic posed aboard a C6 submarine just days after the coup began in 1936.
As Republican resistance collapsed in Catalonia, hundreds of thousands of civilians and soldiers fled toward the French border. Women, children, and the elderly made the journey on foot in winter conditions, desperate to escape the advancing Nationalist forces. Many crossed into France, where they were interned in camps along the coast.
In Washington, D.C., three thousand Spanish-born women marched on the State Department on April 4, led by the widow of an American killed in Spain. They formally called on the U.S. government to revoke its arms embargo against the Republic. Their plea went unanswered. The United States maintained its policy of non-intervention throughout the war, leaving the Republic to rely almost entirely on Soviet support.
The Nationalist leadership consisted of Franco and his senior generals, who coordinated their military strategy from Burgos. General Emilio Mola y Vidal had been the principal architect of the original coup plot, while General José Cavalcanti was among the senior officers who aligned with Franco’s forces from the start.
In Oviedo, the town garrison under Colonel Antonio Aranda Mata declared for the Nationalist uprising and held out against a prolonged Republican siege. The city sustained serious damage before a Nationalist relief force broke through. The siege of Oviedo lasted months and left the city heavily scarred.
Volunteers who had traveled from Britain to fight in the International Brigades began returning home as the war wound down. A wounded member of the International Brigade arrived back at Victoria Station in London on December 19, 1938, after the brigades were formally withdrawn from Spain. The Soviet Union and the Republic had agreed to remove foreign volunteers in a failed bid to persuade Germany and Italy to do the same.
The Battle of the Ebro, fought between July and November 1938, was the longest and largest single battle of the entire war. Franco commanded the Nationalist response as Republican forces crossed the Ebro River in a major offensive. The fighting was concentrated along the lower course of the river, and the Republicans ultimately failed to hold their gains. The defeat effectively sealed the Republic’s fate, leaving Catalonia exposed to the Nationalist advance that followed.
Buenaventura Durruti was one of the most prominent anarchist leaders of the Spanish Civil War, a central figure in the CNT and FAI organizations. He led anarchist militias on the Aragon front and later in the defense of Madrid. He was shot on November 19, 1936 — the circumstances remain disputed, with accounts suggesting he was killed either by an accidental discharge or by enemy fire — and died the following day. His death was a major blow to the anarchist movement within the Republic.
The fall of Barcelona in January 1939 was met with mass celebrations among Nationalist supporters in the city’s Plaza de Catalunya. For Franco, it was the decisive blow. The rest of Catalonia followed within days. The Republican government attempted to negotiate terms, but Franco insisted on unconditional surrender. Madrid held out until March 28, 1939, when it finally capitulated — ending a war that had consumed nearly three years, devastated the country’s cities and countryside, and killed up to a million people. Franco governed Spain with absolute authority until his death in 1975.
