The First International Syndicalist Congress was a meeting of European and Latin American syndicalist organizations at Holborn Town Hall in London from 27 September to 2 October 1913. Upon a proposal by the Dutch National Labour Secretariat (NAS) and the British Industrial Syndicalist Education League (ISEL), most European syndicalist groups, both trade unions and advocacy groups, agreed to congregate at a meeting in London. The only exception was the biggest syndicalist organization worldwide, the French General Confederation of Labour (CGT). Nevertheless, the congress was held with organizations from twelve countries participating. It was marked by heated debate and constant disagreements over both tactics and principles. Yet, it succeeded in creating the International Syndicalist Information Bureau as a vehicle of exchange and solidarity between the various organizations and the Bulletin international du mouvement syndicaliste as a means of communication. It would be viewed as a success by almost all who participated.

Background Syndicalism was a radical current in the labour movement of the early 20th century. Syndicalists viewed class interests as irreconcilable and advocating overthrowing capitalism and replacing it with workers' collectivized control of industry. To this end, syndicalist doctrine emphasized the importance of revolutionary trade unions, independent of all political parties. Unions had to be politically neutral or even hostile to political activity in order to unite the entire working class, though in practice anarchism played a significant role in syndicalist unions. Eschewing political means, syndicalists embraced direct action, particularly the strike, as the most natural weapon in the working class's struggle culminating in a revolutionary general strike. Finally, syndicalists embraced proletarian internationalism as they aimed to overcome national divisions and nationalism.

There was no international syndicalist organization prior to World War I. Syndicalists saw themselves as the heirs of the First International, the international socialist organization formed in 1864. The First International had two wings: one federalist and represented by the followers of Pierre-Joseph Proudhon and later by the anarchist Mikhail Bakunin and a centralist wing represented above all by Karl Marx. Syndicalists identified with the former. In 1889, the Second International was formed as an association of socialist parties and anarchists were expelled in 1893. The International Secretariat of National Trade Union Centers (ISNTUC) brought together trade unions, most of them highly centralized and affiliated with socialist parties. However, the French General Confederation of Labour (Confédération générale du travail in French, CGT), the largest syndicalist organization and the role model for syndicalist unions around the world, and the Dutch National Labour Secretariat (Nationaal Arbeids-Secretariaat in Dutch, NAS) also belonged. They sought to revolutionize ISNTUC from within, with limited success, so the Dutch left in protest in 1907.

In 1909, the NAS declared: "To us it appears [...] necessary that the question of whether the isolation of revolutionary organizations is to be perpetuated should be posed seriously in every country"Quoted by Gras 1971, pg. 86, French original: "Il nous semble [...] nécessaire qu'on se pose sérieusement, dans tous les pays, la quéstion de savoir si l'isolement des organisations révolutionaires doit continuer." and suggested an international syndicalist congress. The Catalan syndicalist group Solidaridad Obrera, which would later become the National Confederation of Labour (CNT), was quick to support this proposal. The CGT was opposed, wanting to remain affiliated with ISNTUC. Such a congress was likely to cause a split between the radical and the reformist wings within the CGT. The French syndicalist leader Pierre Monatte convinced the Dutch to withdraw their proposal.

Invitations In February 1913, the British Industrial Syndicalist Education League (ISEL) and the NAS independently published very similar invitations to an international syndicalist congress. Both criticized the existing labour internationals, especially the reformist social democratic International Secretariat of National Trade Union Centers (ISNTUC), from which, according to the Dutch group, "all revolutionary propaganda [...] is excluded systematically."Quoted by Westergard-Thorpe 1978, pg. 36, French original: "toute propagande révolutionnaire [...] est exclue systématiquement". Likewise, its political counterpart, the Second International, was attacked by the British as a "body that exacts a pledge of parliamentarism and is composed of glib-tongued politicians who promise to do things for us, but cannot even if they wanted."Quoted by Thorpe 1989, pg. 53. Furthermore, the syndicalists lamented the lack of an international syndicalist organization. The British proposal called for the congress to be held in London, while the Dutch left this question open and called for suggestions for the site of the meeting.

The invitations were immediately received warmly by numerous syndicalists, including the Free Association of German Trade Unions (Freie Vereinigung deutscher Gewerkschaften in German, FVdG), Pierre Ramus's journal Wohlstand für Alle from Austria, the Central Organisation of the Workers of Sweden (SAC), the Spanish periodical Tierra y Libertad, the Italian Syndicalist Union (Unione Sindacale Italiana in Italian, USI), the Industrial Workers of the World (IWW) in the United States, and the Syndicalist League of North America. Christiaan Cornelissen, editor of the Bulletin international du mouvement syndicaliste and a prominent anarchist in Paris, also welcomed the idea, but considered the May date proposed by ISEL too soon, as the decentralized decision-making employed by syndicalists required more time for preparation.

French dissent The French General Confederation of Labour (CGT), the largest syndicalist organization in the world, was critical of the proposal. It strove to radicalize ISNTUC from within. While in many countries both radical syndicalist and mainstream socialist labour federations existed, in France, there was only the syndicalist CGT. The FVdG in Germany, for example, where the ISNTUC-affiliated Free Trade Unions would not allow a rival organization from the country to join, did not have this possibility. The CGT wanted to preserve unity within the European labour movement, even with non-syndicalist groups, and was afraid affiliation with a syndicalist international would jeopardize its relations to the mainstream socialist unions. Moreover, the CGT was in a crisis. Reformists were rapidly gaining influence and making it harder to forge alliances with other radical unions.

Syndicalists outside of France rejected the CGT's view. Some held that the CGT could participate in the syndicalist congress while remaining in the ISNTUC. Others felt membership in the social democratic international and syndicalist doctrine were incompatible and considered revolutionizing the social democrats impossible. They warned that the CGT was straying from the revolutionary course by collaborating with the reformist social democrats. They pointed out that the French union already had a considerable reformist wing.

The French responded by pointing to the fact that the British ISEL's domestic policy was similar to its international aims. The ISEL did not constitute a union in its own right, but rather tried to infiltrate and radicalize existing unions, particularly the General Federation of Trade Unions. Pierre Monatte, a CGT leader, declared that if it were to change course, it would harm unionism in all of Europe. He also insisted that it would be impossible for the CGT to both participate in ISNTUC and the syndicalist congress.

Meanwhile, Cornelissen and the ISEL leaders Tom Mann and Guy Bowman adopted a new stance toward the CGT. Bowman expressed confidence that the CGT would change its mind once the congress came around. Mann offered the CGT that it could host the congress. Knowing the CGT as a whole would not change its position, the two attempted to draw the bourses du travail, the regional organizations of the CGT, to participate. Cornelissen, himself active in the French syndicalist movement, explicitly adopted this approach: "Is the French movement organized on the basis of the autonomy of local and regional unions or is it not?", he asked. These approaches were, however, largely unsuccessful, as the CGT leaders, even at a local level, were not impressed.

As the CGT did not participate, the New Statesman would later liken the congress to "playing Hamlet without the Prince of Denmark".

Preparations Discussion turned to the question of what the exact goal of the meeting should be. The Dutch NAS, the British ISEL, and the German FVdG felt that "the creation of an autonomous Syndicalist International is a necessity for the self-preservation and onward development of syndicalism", as Die Einigkeit, the organ of the Germans, put it. Opposition to this view came from two different directions. Cornelissen felt it would easier to attract French unions to a congress meant to establish international relations rather than the foundation of an international organization. Alceste De Ambris, a leader in the Italian USI, on the other hand argued that international secretariats like ISNTUC were useless. He preferred international congresses which could help the national federations break out of their isolation.

Among the organizations endorsing the congress, most wished it take place in the Netherlands. In April, however, ISEL unilaterally announced the congress would take place in late September in London. Not wanting to start a dispute, the Dutch NAS gave in and agreed the meeting would take place in the UK. Soon thereafter problems with the organization of the congress turned up. ISEL was starting to break apart and shaken by internal disputes, especially between the leaders Tom Mann and Guy Bowman. Financial troubles further aggravated these problems. Cornelissen and Albert Jensen of the Swedish SAC voiced their concerns about how the preparations were going in June and July respectively. Bowman, then ISEL's sole leader as Mann was in the United States on a speaking tour, announced the congress would take place from 27 September to 2 October at Holborn Hall in London. He also announced an agenda for the meeting would be appearing soon, but he was not heard from for another while.