He then opened a bookshop with the aim of disseminating anarchist literature, a task to which he devoted himself until in 1934 he was elected General Secretary of the CNT, replacing Joaquín Ascaso Budria and moved to Barcelona.

[3] When the Spanish Civil War broke out, Yoldi was elected Secretary of Defense of Catalonia and faced the military uprising in the streets of Barcelona on 19 July 1936.

[6] In December 1937 he returned to the Aragon front, where he replaced Enric Pérez i Farràs as head of the militia of the 24th Division of the XII Army of the Republic, together with José Manzana Vivó.

[7][8] After the fall of the Aragonese front in the spring of 1938, he was arrested by Republican authorities and his command of the division was withdrawn.

[10] In 1945 he became an adviser to Horacio Martínez Prieto, while he was minister of the José Giral government, and from 1947 until his death he held various positions in the CNT in exile.