Before the Spanish Civil War, he was a major in the Republican Army and a member of UMRA. He was one of the few "Africanistas" officers who remained loyal to the Republican government and led a militia column in the Somosierra front. He led the Republican troops in the Tagus front and reorganized the Republican troops, but he was unable to stop the nationalist offensive. On 24 October he was appointed subsecretary of war by the Prime Minister Largo Caballero and in November 1936 he was appointed commander of the Central army, reorganized the Republican army and aided to form the mixed brigades, merging the militia troops with the remains of the prewar army, the first troops of the republican army capable of open-field fighting. Nevertheless, he was rejected by the communists and the anarchists because he wanted to impose the discipline in the Republican Army and the Soviet ambassador, Rosenberg wanted him to be dismissed. On 21 February 1937 he was dismissed after the fall of Malaga.