[2] As a union organization, and in accordance with its bylaws, the aims of the CNT are to "develop a sense of solidarity among workers", hoping to improve their conditions under the current social system, prepare them for future emancipation, when the means of production have been socialized, to practice mutual aid amongst CNT collectives, and maintain relationships with other like-minded groups hoping for emancipation of the entire working class.

[6] The CNT is rooted in three basic principles: workers' self-management or autogestión, federalism and mutual aid,[7] and considers that work conflicts must be settled between employers and employees without the action of such intermediaries as official state organisms or professional unionists.

[13] Direct representatives of the industry and various posts unions attend the CNT Congress with agreements from their own assemblies, independently from the local and regional levels.

While pure consensus is plausible for individual base unions, higher levels of organizations cannot completely avoid the need for some type of vote, which is always done openly by a show of hands.

However, due to the nature of consensus decision-making, the final agreements consensed to may bear little resemblance to the initial proposals brought to the table.

[24] In 1927 with the "moderate" positioning of some cenetistas (CNT members) the Federación Anarquista Ibérica (FAI), an association of anarchist affinity groups, was created in Valencia.

[26][27] Tensions between the radical faístas, or FAI members, and the moderate non-faístas were constant and difficult to analyze because of the decentralized and sectorial nature of the organization.

[33][34] The first acts of the insurrection took place on January 1, with bombs exploding in La Fulguera, Asturias, and street riots in Seville, Lleida and Pedro Muñoz.

[35] The revolution was violently suppressed: in Bugarra, where the workers had proclaimed libertarian communism after an intense combat with the police, the Guardia Civil retook control of the town and killed 10 peasants while also detaining 250 more.

[36] The most well-known case of repression was the Casas Viejas incident which discredited the government partly leading to its electoral defeat in 1933 elections.

It had its epicenter in Zaragoza and more generally in Aragon and La Rioja and it extended to parts of Extremadura, Andalusia, Catalonia and the mining basin of León.

However, the CNT's Regional Confederation of Labor of Asturias, León and Palencia actively participated in the revolution because of its loyalty to workers' alliances, this time formalized through the Uníos Hermanos Proletarios (UHP; Unite Brothers of the Proletariat)[42] in the pact with the UGT and the Asturian Socialist Federation.

Free love became popular, although some parents' distrust produced the creation of the revolutionary weddings, informal ceremonies in which the couples declared their status, and that could be annulled if both parties didn't want to continue their relationship.

[53] After unsuccessful appeals from the CNT leadership to end the fighting, the government began transferring Assault Guard from the front to Barcelona, and even destroyers from Valencia.

On 5 May, the Friends of Durruti issued a pamphlet calling for "disarming of the paramilitary police… dissolution of the political parties…" and declared "Long live the social revolution!

[54] The next day, the government agreed to a proposal by the leadership of the CNT-FAI, that called for the removal of the Assault Guards, and no reprisals against libertarians that had participated in the conflict, in exchange for the dismantling of barricades, and end of the general strike.

However, neither the PSUC or the Assault Guards gave up their positions, and according to historian Antony Beevor "carried out violent reprisals against libertarians"[55] By 8 May, the fighting was over.

These events, the fall of Largo Caballero's government, and the new prime ministership of Juan Negrín soon led to the collapse of much that the CNT had achieved immediately following the rising the previous July.

At the beginning of July, the Aragonese organizations of the Popular Front publicly declared their support for the alternative council in Aragon, led by their president, Joaquín Ascaso.

[60] In March 1939, with the war nearly over, CNT leaders participated in the National Defense Council's coup overthrowing the government of the Socialist Juan Negrín.

[61] Those involved included the CNT's Eduardo Val and José Manuel González Marín serving on the council, while Cipriano Mera's 70th Division provided military support, and Melechor Rodríquez became mayor of Madrid.

[65] The CNT acted clandestinely inside Spain during the Franco years, as well as conducting activities from exile, and some members kept on fighting the Spanish State until 1948 through the guerrilla actions of maquis.

Even Federica Montseny, who had joined the Republic as Minister of Health changed her stance on collaboration, describing the "futility of...participation in the government.

In September of the next year, a congress was held in Limoges, at which the Sección Defensa Interior (DI) was created, to be partially funded by the CNT.

At a subsequent Extraordinary Congress, held in Torrejón de Ardoz in March–April 1983, the "officials" blocked the "renovators" from speaking or voting, resulting in the passage of anti-electoral resolutions.

[81] On the other side, the syndicalist faction was chiefly concerned with the marginalisation of the CNT in the labour movement, which it believed to have resulted from its failure to organise trade unions.

The syndicalists prioritised union activities and believed that anarcho-syndicalism needed to be updated for modern material conditions; they also advocated for cooperation with other organisations in industrial actions.

The congress resolved to reinforce the CNT's industrial action by hiring a technical team of lawyers and economists, refine its organiser training methods and refocus its efforts on recruiting more members and electing more workplace representatives.

[84] The strategic changes also caused conflict between the CNT and other members of the AIT, particularly the Confederation of Russian Anarcho-Syndicalists [ru] (KRAS) and the Union of Syndicalists of Poland [pl] (ZSP).

[89] Meanwhile, local unions that had split from the CNT held a conference in Villalonga; they established a splinter organisation called the CNT-AIT, which received the official recognition of the AIT.