The Barcelona May Days were a six-day armed revolt within the Republican camp in May 1937, pitting anarchists and Trotskyists against the forces of the Generalitat and the Republican government. Its defeat left more than two hundred antifascists dead and exposed a divided rear at a moment when the Republic was fighting Franco’s forces. In the novel, the episode is not merely a past confrontation: its unresolved political violence shapes Juan Negrín’s distrust of his own institutions and the mission he entrusts to Manuel Arroyo Benítez.

Causes and Course

In early May, anarchists and Trotskyists clashed with the security forces of the Generalitat and the Republican government in Barcelona. They proclaimed a revolution; government forces defeated them after six days of street fighting. The toll—more than two hundred bodies in the city—was especially bitter because the dead were antifascists, killed not by Franco’s side but amid conflict among those resisting it.

The event is presented through the crisis it left behind. Negrín tells Arroyo that the Barcelona uprising had been grave and that the Republic could not afford another. If its factions continued killing one another, he warns, they would lose the war. His alarm does not erase the political causes of the conflict; it expresses the peril of a Republican coalition whose members could agree on opposing Franco while remaining divided over authority, revolution, and the conduct of the war.

Political Consequences

The crisis helped bring down Largo Caballero and preceded Negrín’s rise to the presidency of the government. When Arroyo returned to Madrid in June, the consequences extended beyond the change of leadership. The leadership of the Workers’ Party of Marxist Unification had been arrested in retaliation for the Barcelona fighting, though officials avoided openly describing the arrests that way. Andrés Nin, the party’s leader, had disappeared on 18 May and remained missing even to civilian intelligence bodies within the Republican government.

Nin’s disappearance sharpened the anger of the few POUM supporters in Madrid, who had the backing of many local anarchists. The wider political field was fractured: socialists were divided among themselves, while socialists and communists together outnumbered the anarchists. Their shared support for the government in Valencia and Madrid’s Defense Council was almost the only point of agreement, and even that unity was incomplete. The Barcelona conflict thus continued in Madrid as distrust, factional competition, and secret detention rather than a settled political reconciliation.

Negrín’s Intelligence Problem

The episode directly conditions Negrín’s decision to call on Arroyo. He says he trusts him precisely because he trusts very few people, and admits that he cannot rely on his own side until he establishes order in Republican territory. The Military Intelligence Service, he tells Arroyo, is compromised by competing interests: Soviet advisers exert influence, communists turn a blind eye, and members of Negrín’s own Socialist Party obstruct one another. Anarchists and Trotskyists, meanwhile, continue pursuing their revolution independently, even at the risk of losing the war.

Negrín’s predicament is not simply a choice between political factions. He resents Soviet influence but believes expelling the advisers would mean losing the Soviet Union’s support—the Republic’s only source of aircraft, tanks, and heavy weapons. Breaking with Moscow, he argues, would amount to handing Spain to Franco, an outcome he will not accept. The May fighting therefore stands behind a coercive and morally compromised wartime calculation: restoring order is urgent, but the Republic’s dependence on its allies and the violence within its own camp narrow the available choices.

Longer Shadow

The novel connects the May Days to Arroyo’s later understanding of the Republic’s defeat and its aftermath. In exile, he has heard too many declarations of loyalty from people who then betrayed the Republic, and he continues his intelligence work despite wanting relief from the strain. His experience sustains pressure on those who know more than they admit; it also leaves him distrustful of political assurances. The memory of internal division is one part of a wider postwar disillusionment, as the Western powers’ priorities shift toward anticommunism and away from the Republic’s claim to justice.

The Barcelona fighting also frames a recurring danger in the story: political language that treats repression as necessary for security can obscure who is being detained, whose disappearance is being ignored, and which political interests are being protected. The revolt’s defeat did not end the conflict within Republican society. Its consequences—arrests, Nin’s disappearance, and Negrín’s anxious reliance on intelligence—show how a struggle against fascism could be weakened by violence and suspicion within the antifascist camp itself.