When people first encounter the Spanish Civil War, one of the most confusing aspects is the enormous influence of anarchism in Republican Spain, particularly in Barcelona and across large parts of Catalonia and Aragón. Modern readers often associate the word ‘anarchy’ with disorder, lawlessness, or the complete absence of organisation. In popular culture, the term is frequently used as a synonym for chaos. The anarchists of 1936 Spain would have rejected that definition. Far from seeking disorder, they believed they were creating a different kind of social order. Instead of governments, monarchies, military elites, large corporations, and traditional political institutions directing society from above, anarchists argued that ordinary people should organise themselves through workplaces, neighbourhood assemblies, cooperatives, trade unions, and voluntary associations. They believed society could function through cooperation rather than coercion and through collective decision-making rather than hierarchical authority.

Whether one agrees with these ideas or not, it is important to understand that Spanish anarchists did not see themselves as destroying society. They believed they were rebuilding it on different foundations. By July 1936, anarchism was not a marginal political current in Spain. It was one of the largest mass movements in the country and arguably the most influential anarchist movement anywhere in the world. This can surprise modern readers because anarchism never achieved comparable influence in most other European countries. In Spain, anarchist ideas found fertile ground among both industrial workers and agricultural labourers. The reasons were rooted in the country’s social and economic history.

During the late nineteenth and early twentieth centuries, many Spanish workers experienced low wages, poor working conditions, limited political representation, and repeated cycles of labour unrest. Industrial cities like Barcelona developed strong traditions of trade unionism and worker activism. In the countryside, particularly in parts of Andalucía and Aragón, large estates owned by wealthy landowners existed alongside widespread rural poverty and landlessness. For many workers and labourers, conventional politics seemed incapable of solving these problems. Governments changed, elections came and went, but social inequalities remained. Anarchism offered an alternative vision that promised both economic justice and greater personal freedom.

The movement also drew strength from Spain’s long history of conflict between labour organisations, employers, the military, and the Catholic Church. In Barcelona especially, the early twentieth century had been marked by strikes, lockouts, police repression, political assassinations, and violent confrontations between workers and employers. Entire generations grew up in an atmosphere where political conflict was not an abstract concept but part of daily life. As a result, anarchism in Spain became more than a political theory. It became a culture, a social movement, and a way of understanding the world. Anarchist organisations established newspapers, schools, libraries, cultural centres, educational programmes, and mutual-aid networks. They organised lectures, published literature, promoted literacy, and encouraged political discussion among ordinary workers. For many supporters, anarchism was not simply about future revolution. It was something that shaped everyday life in the present.

Barcelona became the movement’s most important centre. The city was Spain’s leading industrial metropolis and possessed one of Europe’s largest concentrations of organised labour. Factories, workshops, docks, railway yards, and industrial districts brought together large numbers of workers who often faced similar economic conditions and political grievances. By the 1930s, anarchist organisations had become deeply embedded in many working-class neighbourhoods. This helps explain why events unfolded as they did in July 1936.  The organisations that resisted the military rebellion had often spent decades building local networks, recruiting members, publishing newspapers, organising strikes, and developing structures capable of mobilising thousands of people quickly. The ability of Barcelona’s workers to respond to the uprising was rooted in years of organisation before the first shots of the Civil War were fired. For many anarchists, the military rebellion represented more than an attack on the Republic. It threatened everything they had spent years building. Trade unions, workers’ centres, educational projects, community organisations, and political freedoms all appeared to be at risk.

The central organisation of Spanish anarchism was the Confederación Nacional del Trabajo, usually known simply as the CNT. Founded in Barcelona in 1910, the CNT was far more than a trade union in the modern sense. It functioned simultaneously as a labour organisation, a social movement, an educational network, and, for many supporters, a vision of a future society. By the 1930s it had become one of the largest revolutionary labour organisations in the world. Membership fluctuated considerably because of government repression, economic conditions, and internal disputes, but by the mid-1930s the CNT claimed well over one million members. During some periods it approached or exceeded one and a half million. Precise figures remain debated by historians,  there is broad agreement that it represented a substantial portion of Spain’s organised working class.

Although Catalonia remained the organisation’s strongest centre, CNT unions operated across much of Spain. Membership was particularly strong among industrial workers in Barcelona, Valencia, Zaragoza, and other urban centres. It also attracted large numbers of agricultural labourers in Andalucía, Aragón, Extremadura, and parts of Levante. Dock workers, railway workers, construction labourers, metalworkers, textile workers, printers, transport employees, and agricultural workers could all be found within its ranks. What united these diverse groups was not a shared occupation but a shared belief that workers should control their own lives and workplaces.

The CNT rejected the idea that political parties or governments could solve the problems facing ordinary people. Instead, it argued that workers themselves should organise society through federations of unions. Factories, railways, farms, workshops, ports, and public services would ultimately be managed by those who worked within them rather than by employers, shareholders, politicians, or state officials. This ideology became known as anarcho-syndicalism. To many outsiders, the concept appeared radical or unrealistic. To many CNT members, it seemed entirely practical. Workers already possessed the skills necessary to operate factories, transport systems, farms, and public services. The CNT’s structure reflected these beliefs. Rather than concentrating authority in a small leadership elite, the organisation was built around local unions, assemblies, and federations. Decisions were theoretically made from the bottom upward. Delegates could represent members at higher levels, but they were expected to carry out decisions rather than impose them. This emphasis on direct participation became one of the defining features of Spanish anarchism.

The organisation also developed a reputation for militancy. During the early twentieth century, Spain experienced repeated cycles of strikes, lockouts, repression, and political violence. The CNT often stood at the centre of these confrontations. Major strikes in Barcelona and other cities brought workers into direct conflict with employers, police, and the military. Governments periodically banned the organisation, imprisoned its members, closed its newspapers, and attempted to dismantle its networks. These experiences reinforced a widespread belief among CNT members that the state ultimately served the interests of employers and powerful social groups rather than ordinary workers.

The years after the First World War proved especially important. In 1919, the famous La Canadiense strike in Barcelona demonstrated the organisation’s growing strength. What began as a dispute involving workers at a power company expanded into a broader strike that paralysed much of the city and eventually forced the government to introduce the eight-hour working day, making Spain one of the first countries in the world to adopt it nationally. For many workers, this victory demonstrated that collective action could achieve results that conventional politics had failed to deliver.

The CNT also sponsored newspapers, reading groups, educational programmes, cultural centres, and community activities. In many working-class districts, union offices served as social and political hubs where people discussed current events, attended lectures, borrowed books, and participated in local campaigns. Anarchists believed education was essential because workers needed knowledge as well as organisation if they were to build a different society. As a result, membership in the CNT  could shape an individual’s political outlook, social relationships, and daily life.

Women also participated in the organisation, although not always on equal terms. Female workers joined unions, attended meetings, contributed to publications, and participated in strikes and labour campaigns.  leadership positions remained overwhelmingly male, and many women later criticised the gap between anarchist ideals of equality and the realities they experienced within the movement. These frustrations would contribute to the creation of Mujeres Libres during the Civil War.

By the time the Second Republic was established in 1931, the CNT had become one of the most influential political and social forces in Spain. The organisation’s relationship with the Republic was complicated. Many members welcomed the fall of the monarchy, but they remained sceptical of parliamentary politics. They supported reforms that improved workers’ lives while continuing to argue that genuine emancipation required a more fundamental transformation of society. Throughout the early 1930s, the CNT participated in strikes, protests, and occasional insurrectionary actions that brought it into conflict with successive governments. Then, the Civil War revealed how important the organisation had already become. The ability of Barcelona’s workers to resist the uprising, organise militias, seize weapons, and maintain control over much of the city was built upon decades of prior organisation.

Alongside the CNT operated the Federación Anarquista Ibérica, or FAI. Compared to the CNT, the FAI was much smaller. It never possessed hundreds of thousands of members and did not function as a mass trade union organisation. Instead, it operated as a network of committed anarchist groups spread across Spain and Portugal. Membership was probably measured in the thousands rather than the hundreds of thousands, though precise figures remain difficult to establish because the organisation’s structure was intentionally decentralised. Despite its relatively small size, the FAI exercised influence far beyond its numbers because it offered alternatives to the CNT. As the CNT grew during the early twentieth century, many anarchists worried that it might gradually become a conventional labour organisation concerned more with reform than revolution, and so the FAI emerged partly in response to these concerns.

Founded in 1927, during the dictatorship of General Miguel Primo de Rivera, the FAI sought to preserve what its members regarded as the revolutionary essence of Spanish anarchism. They feared that participation in legal politics, negotiations with governments, or routine trade-union activity might dilute anarchist principles and weaken the movement’s long-term goals. The FAI  acted less like a political party and more like a revolutionary current operating within the broader anarchist movement. Its members organised through small affinity groups, often composed of trusted friends and comrades who shared similar political views. These groups coordinated activities, discussed strategy, distributed literature, and attempted to influence the direction of the wider movement. The structure reflected anarchist distrust of rigid hierarchies and centralised authority.

Many prominent anarchist figures belonged to both the CNT and the FAI. As a result, the distinction between the two organisations can sometimes appear blurred. The CNT remained the mass organisation rooted in workplaces and trade unions, while the FAI represented a more explicitly revolutionary tendency operating within and alongside it. Historians often describe the relationship as complex because individuals frequently moved between both worlds. By the early 1930s, critics and supporters alike increasingly referred to the combined influence of CNT-FAI.

The FAI became particularly influential during the years of the Second Republic. While some political groups welcomed parliamentary democracy as the path to reform, many faístas remained deeply sceptical of elected governments. They argued that genuine social change would not come through elections, ministries, or political parties. Instead, they believed transformation would emerge through direct action by workers and communities themselves. This outlook contributed to a series of confrontations with Republican authorities. During the early 1930s, sections of the anarchist movement participated in strikes, uprisings, and insurrectionary attempts that sought to accelerate social revolution. Some of these efforts ended in failure and brought severe repression. Events like the uprising at Casas Viejas in 1933, where government forces brutally suppressed anarchist activists and villagers, reinforced distrust of state institutions among many militants. For FAI members, such incidents appeared to confirm their belief that governments of all kinds ultimately relied upon coercion and violence.

The FAI’s influence was particularly strong in Barcelona. The city possessed a long tradition of radical labour politics, anti-clericalism, and working-class activism. In neighbourhoods across Barcelona, anarchist ideas circulated through union halls, newspapers, cultural centres, and informal social networks. Many younger militants were drawn toward the FAI because of its uncompromising commitment to revolution. This revolutionary culture became critically important in July 1936. When the military uprising began, faístas were among the activists who pushed for immediate resistance. Years of organising, clandestine activity, and preparation for confrontation had created networks capable of mobilising rapidly. While loyal police and security forces played a crucial role in defeating the rebellion in Barcelona, anarchist militants were also central participants in the fighting. The defeat of the uprising appeared to vindicate many of the FAI’s long-held arguments.

For supporters, the FAI represented a commitment to revolutionary principles at a moment when compromise seemed tempting. For critics, it represented ideological rigidity and political impracticality. Both interpretations contain elements of truth and what cannot be disputed is the organisation’s influence during the summer of 1936. Although small compared to the CNT, the FAI helped shape the ideas, language, and aspirations of much of the anarchist movement. Its members were among those most determined to ensure that the defeat of the military uprising became not merely a military victory, but the beginning of a social revolution.

Why Did Anarchism Flourish in Spain? Anarchist movements existed throughout Europe during the late nineteenth and early twentieth centuries. France, Italy, Portugal, Russia, Britain, Germany, and the United States all possessed anarchist organisations of varying sizes.  Nowhere did anarchism become as deeply rooted among ordinary workers and labourers as it did in Spain. The CNT alone claimed well over one million members at various points during the decade. Even allowing for the exaggerations common in union membership figures, historians generally agree that hundreds of thousands of Spaniards belonged to anarchist organisations. Millions more lived in communities where anarchist ideas, newspapers, trade unions, cultural centres, and social networks formed part of everyday life. In Barcelona, entire neighbourhoods contained generations of families connected to anarchist organisations. In parts of Aragón and Andalucía, anarchist ideas spread among agricultural workers who often possessed little land and few opportunities. Railway workers, dock workers, textile workers, metalworkers, printers, builders, and farm labourers all contributed to the movement’s growth.

Spain entered the twentieth century with profound social inequalities. Large sections of the population remained poor. Industrial workers often faced long hours, dangerous conditions, and insecure employment. In rural regions, vast estates owned by wealthy landowners existed alongside communities of landless labourers who struggled to find regular work. For many Spaniards, the existing political system appeared incapable of solving these problems. Governments changed frequently, the monarchies fell, dictatorships rose and collapsed. Elections produced new politicians but often little visible improvement in daily life. Corruption, patronage, and political instability undermined confidence in traditional institutions.

Rather than asking workers to trust politicians, anarchists argued that workers should organise society themselves. Factories would be run by those who worked in them. Farms would be cultivated collectively. Communities would govern themselves through assemblies and federations. Education would be expanded. Economic privilege would be dismantled. The vision was ambitious, but it spoke directly to people who felt excluded from existing structures of power.

Spain also lacked some of the factors that helped contain revolutionary movements elsewhere. In countries like Britain and Germany, large socialist parties gradually became integrated into parliamentary politics. Trade unions often focused on negotiating reforms within existing systems. In Spain, political institutions were generally weaker and labour conflicts more intense. As a result, revolutionary ideas retained greater appeal for longer periods.

In 1936, for supporters of the Republic, the victory against the military uprising was one of the most significant achievements of the war’s opening days. Lluís Companys, president of the Catalonian Generalitat, recognised this reality almost immediately. In one of the most famous meetings of the revolutionary period, Companys met with leading CNT figures shortly after the defeat of the uprising. He acknowledged that the anarchists had played a decisive role in saving Catalonia and admitted that real power now rested largely with the armed workers who controlled the streets. The CNT leadership faced a historic decision. For decades anarchists had criticised governments and state institutions. Now they possessed more influence than at any point in their history. Some militants believed the moment had arrived to abolish existing institutions entirely and replace them with revolutionary organisations. Others feared that doing so would fracture anti-fascist unity and weaken the struggle against the rebellion. Rather than immediately replacing the Generalitat, anarchist leaders agreed to cooperate with other anti-fascist organisations through the newly created Central Committee of Antifascist Militias of Catalonia. They intended to defeat the military rebellion, but they also hoped to spread revolutionary change beyond Catalonia. For many anarchists, the war against fascism and the social revolution were inseparable.

Across Europe, observers watched events with fascination, admiration, or alarm. Supporters saw evidence that ordinary people could reshape society. Critics saw chaos and the breakdown of authority. Both recognised that something extraordinary was taking place. For a brief period during the summer of 1936, the CNT and FAI found themselves at the centre of one of the largest social revolutions in modern European history. Decades of organisation had prepared them for resistance. The collapse of the military uprising provided the opportunity. The result was a revolutionary experiment whose influence would extend far beyond Barcelona and far beyond Spain itself.