Cipriano Mera was born in Spain in 1879. An anarchist, he became a construction worker in Madrid. A member of the National Confederation of Trabajo (CNT), in December 1933 he joined with fellow anarchist, Buenaventura Durruti, to establish the Revolutionary Committee of Saragossa. This resulted in Mera being arrested and imprisoned in Burgos.
In June 1936 Mera led a strike of construction workers, electricians, and elevator operators in Saragossa. On the outbreak of the Spanish Civil War a few months later, he was given command of the 14th Division.
Mera participated in all the major battles on the central front and played a prominent role in the Republican Army victory at Guadalajara in March 1937.
By 1939 Mera was convinced that the Republicans would be defeated. When Juan Negrin refused to negotiate a peace agreement with General Francisco Franco, Mera joined with Segismundo Casado, commander of the Republican Army of the Centre, and Julián Besteiro of the Socialist Party, to establish an anti-Negrin National Defence Junta.
On 6th March José Miaja in Madrid joined the rebellion by ordering the arrests of Communists in the city. Negrin, about to leave for France, ordered Luis Barceló, commander of the First Corps of the Army of the Centre, to try and regain control of the capital. His troops entered Madrid and there was fierce fighting for several days in the city until Mera's troops managed to defeat the First Corps.
Segismundo Casado now tried to negotiate a peace settlement with General Francisco Franco. However, he refused demanding an unconditional surrender. Members of the Republican Army still left alive, were no longer willing to fight and the Nationalist Army entered Madrid virtually unopposed on 27th March.
Mera fled to Algeria where he was arrested and jailed for seven years. On his release he moved to France where he worked as a bricklayer until his death in Paris in 1975.