During the Fascist uprising, at the beginning of the Spanish Civil War, he went to Barcelona and joined the Durruti Column[1] of Confederación Nacional del Trabajo (CNT) militiamen in their attempt to liberate Zaragoza (Aragon).

He was denounced and then captured by the Francoist troops as he crossed the Guadalaviar (Turia) in the Sierra de Albarracín on a mission at the beginning of the Catalonia Offensive on 18 December 1938.

[8] After several concentration camps (Santa Eulalia del Campo, Calataiud), interrogations, torture and mock executions, he managed to falsify his prison record and was released on parole on 10 August 1944.

[10] Rufat was also put in charge of propaganda, relaunching the clandestine publications of the internal resistance of the Libertarian Movement (ML) and CNT, in particular Solidaridad Obrera, Fragua Social, Tierra y Libertad, which had been banned.

This was the "golden age" of the anarchist resistance to Franco's regime, with a wide distribution of the underground press in the regions, the first major strikes in 1945 in Barcelona and then in Vizcaya, the first demonstrations, and then the resumption of urban guerrilla warfare, notably with attacks on banks.

[11] He continued the underground revolutionary struggle until he was arrested alongside the whole clandestine Ninth CNT National Committee on 6 October 1945 in Madrid by the Francoist Political-Social Brigade.

[16] This led him to devote the rest of his life to writing "the history of the defeated", in particular by collaborating with the Bibliothèque de documentation internationale contemporaine (BDIC) at the University of Nanterre.